diff --git a/appveyor.yml b/appveyor.yml
index f8621519..25b10a5c 100644
--- a/appveyor.yml
+++ b/appveyor.yml
@@ -1,5 +1,8 @@
 environment:
   matrix:
+    - LWS_METHOD: x64
+      CMAKE_ARGS: -DCMAKE_GENERATOR_PLATFORM=x64 -DLWS_WITH_HTTP2=1 -DLWS_WITH_PLUGINS=1 -DLIBUV_INCLUDE_DIRS=C:\assets\libuv64\include -DLIBUV_LIBRARIES=C:\assets\libuv64\libuv.lib
+
     - LWS_METHOD: lwsws
       CMAKE_ARGS: -DLWS_WITH_LWSWS=1 -DSQLITE3_INCLUDE_DIRS=C:\assets\sqlite3 -DSQLITE3_LIBRARIES=C:\assets\sqlite3\sqlite3.lib -DLIBUV_INCLUDE_DIRS=C:\assets\libuv\include -DLIBUV_LIBRARIES=C:\assets\libuv\libuv.lib
 
@@ -21,6 +24,9 @@ install:
   - mkdir c:\assets
   - mkdir c:\assets\libuv
   - 7z x -oc:\assets\libuv win-libuv.zip
+  - appveyor DownloadFile https://libwebsockets.org:444/win-libuv64.zip
+  - mkdir c:\assets\libuv64
+  - 7z x -oc:\assets\libuv64 win-libuv64.zip
   - appveyor DownloadFile https://libwebsockets.org:444/nsis-3.0rc1-setup.exe
   - cmd /c start /wait nsis-3.0rc1-setup.exe /S /D=C:\nsis
   - appveyor DownloadFile https://libwebsockets.org:444/sqlite-dll-win32-x86-3130000.zip
diff --git a/lib/client/client-handshake.c b/lib/client/client-handshake.c
index c2720d92..c07a630e 100644
--- a/lib/client/client-handshake.c
+++ b/lib/client/client-handshake.c
@@ -344,7 +344,7 @@ lws_client_connect_2(struct lws *wsi)
 			goto failed;
 		wsi->c_port = wsi->vhost->http_proxy_port;
 
-		n = send(wsi->desc.sockfd, (char *)pt->serv_buf, plen,
+		n = send(wsi->desc.sockfd, (char *)pt->serv_buf, (int)plen,
 			 MSG_NOSIGNAL);
 		if (n < 0) {
 			lwsl_debug("ERROR writing to proxy socket\n");
diff --git a/lib/client/client.c b/lib/client/client.c
index 81950458..98365725 100644
--- a/lib/client/client.c
+++ b/lib/client/client.c
@@ -37,8 +37,7 @@ lws_handshake_client(struct lws *wsi, unsigned char **buf, size_t len)
 			 * we were accepting input but now we stopped doing so
 			 */
 			if (lws_is_flowcontrolled(wsi)) {
-				lwsl_debug("%s: caching %ld\n", __func__,
-					   (long)len);
+				lwsl_debug("%s: caching %ld\n", __func__, (long)len);
 				lws_rxflow_cache(wsi, *buf, 0, (int)len);
 				return 0;
 			}
@@ -318,8 +317,7 @@ start_ws_handshake:
 		/* send our request to the server */
 		lws_latency_pre(context, wsi);
 
-		n = lws_ssl_capable_write(wsi, (unsigned char *)sb,
-					  (int)(p - sb));
+		n = lws_ssl_capable_write(wsi, (unsigned char *)sb, (int)(p - sb));
 		lws_latency(context, wsi, "send lws_issue_raw", n,
 			    n == p - sb);
 		switch (n) {
@@ -809,7 +807,7 @@ lws_client_interpret_server_handshake(struct lws *wsi)
 	}
 
 	p = lws_hdr_simple_ptr(wsi, WSI_TOKEN_PROTOCOL);
-	len = strlen(p);
+	len = (int)strlen(p);
 
 	while (pc && *pc && !okay) {
 		if (!strncmp(pc, p, len) &&
@@ -966,8 +964,7 @@ check_extensions:
 
 			if (ext_name[0] &&
 			    lws_ext_parse_options(ext, wsi, wsi->act_ext_user[
-						  wsi->count_act_ext], opts,
-						  ext_name,
+						  wsi->count_act_ext], opts, ext_name,
 						  (int)strlen(ext_name))) {
 				lwsl_err("%s: unable to parse user defaults '%s'",
 					 __func__, ext_name);
@@ -980,7 +977,7 @@ check_extensions:
 			 */
 			if (a && lws_ext_parse_options(ext, wsi,
 					wsi->act_ext_user[wsi->count_act_ext],
-					opts, a, c - a)) {
+					opts, a, lws_ptr_diff(c, a))) {
 				lwsl_err("%s: unable to parse remote def '%s'",
 					 __func__, a);
 				cce = "HS: EXT: failed parsing options";
@@ -1062,7 +1059,7 @@ check_accept:
 	 * size mentioned in the protocol definition.  If 0 there, then
 	 * use a big default for compatibility
 	 */
-	n = wsi->protocol->rx_buffer_size;
+	n = (int)wsi->protocol->rx_buffer_size;
 	if (!n)
 		n = context->pt_serv_buf_size;
 	n += LWS_PRE;
diff --git a/lib/event-libs/libuv.c b/lib/event-libs/libuv.c
index e88f1cff..abacb16c 100644
--- a/lib/event-libs/libuv.c
+++ b/lib/event-libs/libuv.c
@@ -333,7 +333,7 @@ lws_libuv_accept(struct lws *wsi, lws_sock_file_fd_type desc)
 	wsi->w_read.context = context;
 	if (wsi->mode == LWSCM_RAW_FILEDESC || wsi->event_pipe)
 		uv_poll_init(pt->io_loop_uv, &wsi->w_read.uv_watcher,
-			     (int)desc.filefd);
+			     (int)(long long)desc.filefd);
 	else
 		uv_poll_init_socket(pt->io_loop_uv, &wsi->w_read.uv_watcher,
 				    desc.sockfd);
diff --git a/lib/ext/extension-permessage-deflate.c b/lib/ext/extension-permessage-deflate.c
index 210d4629..d26f63af 100644
--- a/lib/ext/extension-permessage-deflate.c
+++ b/lib/ext/extension-permessage-deflate.c
@@ -51,7 +51,7 @@ lws_extension_pmdeflate_restrict_args(struct lws *wsi,
 
 	n = wsi->context->pt_serv_buf_size;
 	if (wsi->protocol->rx_buffer_size)
-		n =  wsi->protocol->rx_buffer_size;
+		n = (int)wsi->protocol->rx_buffer_size;
 
 	extra = 7;
 	while (n >= 1 << (extra + 1))
@@ -120,7 +120,7 @@ lws_extension_callback_pm_deflate(struct lws_context *context,
 
 		n = context->pt_serv_buf_size;
 		if (wsi->protocol->rx_buffer_size)
-			n =  wsi->protocol->rx_buffer_size;
+			n = (int)wsi->protocol->rx_buffer_size;
 
 		if (n < 128) {
 			lwsl_info(" permessage-deflate requires the protocol (%s) to have an RX buffer >= 128\n",
@@ -302,7 +302,7 @@ lws_extension_callback_pm_deflate(struct lws_context *context,
 			priv->rx_held_valid = 1;
 		}
 
-		eff_buf->token_len = (char *)priv->rx.next_out - eff_buf->token;
+		eff_buf->token_len = lws_ptr_diff(priv->rx.next_out, eff_buf->token);
 		priv->count_rx_between_fin += eff_buf->token_len;
 
 		lwsl_ext("  %s: RX leaving with new effbuff len %d, "
@@ -398,8 +398,8 @@ lws_extension_callback_pm_deflate(struct lws_context *context,
 			}
 		}
 		priv->compressed_out = 1;
-		eff_buf->token_len = (int)(priv->tx.next_out -
-					   (unsigned char *)eff_buf->token);
+		eff_buf->token_len = lws_ptr_diff(priv->tx.next_out,
+						  eff_buf->token);
 
 		/*
 		 * we must announce in our returncode now if there is more
diff --git a/lib/ext/extension.c b/lib/ext/extension.c
index ac282040..d4c227d2 100644
--- a/lib/ext/extension.c
+++ b/lib/ext/extension.c
@@ -121,7 +121,7 @@ lws_ext_parse_options(const struct lws_extension *ext, struct lws *wsi,
 				return -1;
 			leap = LEAPS_SEEK_ARG_TERM;
 			if (oa.start)
-				oa.len = in - oa.start;
+				oa.len = lws_ptr_diff(in, oa.start);
 			if (len == 1)
 				oa.len++;
 
@@ -218,7 +218,7 @@ lws_issue_raw_ext_access(struct lws *wsi, unsigned char *buf, size_t len)
 	int ret, m, n = 0;
 
 	eff_buf.token = (char *)buf;
-	eff_buf.token_len = len;
+	eff_buf.token_len = (int)len;
 
 	/*
 	 * while we have original buf to spill ourselves, or extensions report
@@ -294,7 +294,7 @@ lws_issue_raw_ext_access(struct lws *wsi, unsigned char *buf, size_t len)
 		ret = 0;
 	}
 
-	return len;
+	return (int)len;
 }
 
 int
diff --git a/lib/handshake.c b/lib/handshake.c
index bc7609d9..94bd881f 100644
--- a/lib/handshake.c
+++ b/lib/handshake.c
@@ -82,7 +82,7 @@ lws_read(struct lws *wsi, unsigned char *buf, lws_filepos_t len)
 			 * we were accepting input but now we stopped doing so
 			 */
 			if (lws_is_flowcontrolled(wsi)) {
-				lws_rxflow_cache(wsi, buf, n, len);
+				lws_rxflow_cache(wsi, buf, (int)n, (int)len);
 
 				return 1;
 			}
@@ -271,7 +271,7 @@ read_ok:
 	/* Nothing more to do for now */
 	lwsl_info("%s: read_ok, used %ld\n", __func__, (long)(buf - oldbuf));
 
-	return buf - oldbuf;
+	return lws_ptr_diff(buf, oldbuf);
 
 bail:
 	lws_close_free_wsi(wsi, LWS_CLOSE_STATUS_NOSTATUS);
diff --git a/lib/header.c b/lib/header.c
index e2562cd6..7930e76b 100644
--- a/lib/header.c
+++ b/lib/header.c
@@ -196,7 +196,7 @@ lws_add_http_header_status(struct lws *wsi, unsigned int _code,
 		if (lws_add_http_header_by_name(wsi,
 				(const unsigned char *)headers->name,
 				(unsigned char *)headers->value,
-				strlen(headers->value), p, end))
+				(int)strlen(headers->value), p, end))
 			return 1;
 
 		headers = headers->next;
@@ -242,7 +242,7 @@ lws_return_http_status(struct lws *wsi, unsigned int code,
 					 &p, end))
 		return 1;
 
-	len = 35 + strlen(html_body) + sprintf(slen, "%d", code);
+	len = 35 + (int)strlen(html_body) + sprintf(slen, "%d", code);
 	n = sprintf(slen, "%d", len);
 
 	if (lws_add_http_header_by_token(wsi, WSI_TOKEN_HTTP_CONTENT_LENGTH,
@@ -270,7 +270,7 @@ lws_return_http_status(struct lws *wsi, unsigned int code,
 		 * Solve it by writing the headers now...
 		 */
 		m = lws_write(wsi, start, p - start, LWS_WRITE_HTTP_HEADERS);
-		if (m != (int)(p - start))
+		if (m != lws_ptr_diff(p, start))
 			return 1;
 
 		/*
@@ -305,7 +305,7 @@ lws_return_http_status(struct lws *wsi, unsigned int code,
 				  "<html><body><h1>%u</h1>%s</body></html>",
 				  code, html_body);
 
-		n = (int)(p - start);
+		n = lws_ptr_diff(p, start);
 
 		m = lws_write(wsi, start, n, LWS_WRITE_HTTP);
 		if (m != n)
diff --git a/lib/http2/hpack.c b/lib/http2/hpack.c
index 707de1f1..6533bcbc 100644
--- a/lib/http2/hpack.c
+++ b/lib/http2/hpack.c
@@ -357,7 +357,7 @@ lws_token_from_index(struct lws *wsi, int index, const char **arg, int *len,
 	if (index < (int)ARRAY_SIZE(static_token)) {
 		if (arg && index < (int)ARRAY_SIZE(http2_canned)) {
 			*arg = http2_canned[index];
-			*len = strlen(http2_canned[index]);
+			*len = (int)strlen(http2_canned[index]);
 		}
 		if (hdr_len)
 			*hdr_len = static_hdr_len[index];
@@ -1301,7 +1301,7 @@ int lws_add_http2_header_by_name(struct lws *wsi, const unsigned char *name,
 
 	lwsl_header("%s: %p  %s:%s\n", __func__, *p, name, value);
 
-	len = strlen((char *)name);
+	len = (int)strlen((char *)name);
 	if (len)
 		if (name[len - 1] == ':')
 			len--;
diff --git a/lib/http2/http2.c b/lib/http2/http2.c
index a78e1613..da893ff6 100644
--- a/lib/http2/http2.c
+++ b/lib/http2/http2.c
@@ -633,7 +633,8 @@ int lws_h2_do_pps_send(struct lws *wsi)
 		h2n->we_told_goaway = 1;
 		n = lws_h2_frame_write(wsi, LWS_H2_FRAME_TYPE_GOAWAY, 0,
 				       LWS_H2_STREAM_ID_MASTER,
-				       p - &set[LWS_PRE], &set[LWS_PRE]);
+				       lws_ptr_diff(p, &set[LWS_PRE]),
+				       &set[LWS_PRE]);
 		if (n != 4) {
 			lwsl_info("send %d %d\n", n, m);
 			goto bail;
diff --git a/lib/libwebsockets.c b/lib/libwebsockets.c
index 91bf5173..eee82e84 100644
--- a/lib/libwebsockets.c
+++ b/lib/libwebsockets.c
@@ -245,7 +245,7 @@ lws_bind_protocol(struct lws *wsi, const struct lws_protocols *p)
 		return 1;
 
 	if (p > vp && p < &vp[wsi->vhost->count_protocols])
-		lws_same_vh_protocol_insert(wsi, p - vp);
+		lws_same_vh_protocol_insert(wsi, (int)(p - vp));
 	else {
 		int n = wsi->vhost->count_protocols;
 		int hit = 0;
@@ -255,7 +255,7 @@ lws_bind_protocol(struct lws *wsi, const struct lws_protocols *p)
 		while (n--) {
 			if (p->name && vp->name && !strcmp(p->name, vp->name)) {
 				hit = 1;
-				lws_same_vh_protocol_insert(wsi, vp - vpo);
+				lws_same_vh_protocol_insert(wsi, (int)(vp - vpo));
 				break;
 			}
 			vp++;
@@ -847,7 +847,7 @@ lws_close_free_wsi_final(struct lws *wsi)
 LWS_VISIBLE LWS_EXTERN const char *
 lws_get_urlarg_by_name(struct lws *wsi, const char *name, char *buf, int len)
 {
-	int n = 0, sl = strlen(name);
+	int n = 0, sl = (int)strlen(name);
 
 	while (lws_hdr_copy_fragment(wsi, buf, len,
 			  WSI_TOKEN_HTTP_URI_ARGS, n) >= 0) {
@@ -1312,7 +1312,7 @@ lws_now_secs(void)
 
 #if LWS_POSIX
 
-LWS_VISIBLE int
+LWS_VISIBLE lws_sockfd_type
 lws_get_socket_fd(struct lws *wsi)
 {
 	if (!wsi)
@@ -1471,7 +1471,7 @@ lws_set_proxy(struct lws_vhost *vhost, const char *proxy)
 
 		strncpy(authstring, proxy, p - proxy);
 		// null termination not needed on input
-		if (lws_b64_encode_string(authstring, (p - proxy),
+		if (lws_b64_encode_string(authstring, lws_ptr_diff(p, proxy),
 				vhost->proxy_basic_auth_token,
 		    sizeof vhost->proxy_basic_auth_token) < 0)
 			goto auth_too_long;
@@ -1985,7 +1985,7 @@ lws_close_reason(struct lws *wsi, enum lws_close_status status,
 		while (len-- && p < start + budget)
 			*p++ = *buf++;
 
-	wsi->u.ws.close_in_ping_buffer_len = p - start;
+	wsi->u.ws.close_in_ping_buffer_len = lws_ptr_diff(p, start);
 }
 
 LWS_EXTERN int
@@ -2552,7 +2552,7 @@ lws_snprintf(char *str, size_t size, const char *format, ...)
 	va_end(ap);
 
 	if (n >= (int)size)
-		return size;
+		return (int)size;
 
 	return n;
 }
diff --git a/lib/libwebsockets.h b/lib/libwebsockets.h
index 9c756d30..f611b387 100644
--- a/lib/libwebsockets.h
+++ b/lib/libwebsockets.h
@@ -4752,7 +4752,7 @@ lws_callback_http_dummy(struct lws *wsi, enum lws_callback_reasons reason,
  *
  * \param wsi:	Websocket connection instance
  */
-LWS_VISIBLE LWS_EXTERN int
+LWS_VISIBLE LWS_EXTERN lws_sockfd_type
 lws_get_socket_fd(struct lws *wsi);
 
 /**
@@ -5130,6 +5130,18 @@ lws_interface_to_sa(int ipv6, const char *ifname, struct sockaddr_in *addr,
 	} \
 }
 
+/**
+ * lws_ptr_diff(): helper to report distance between pointers as an int
+ *
+ * \param head: the pointer with the larger address
+ * \param tail: the pointer with the smaller address
+ *
+ * This helper gives you an int representing the number of bytes further
+ * forward the first pointer is compared to the second pointer.
+ */
+#define lws_ptr_diff(head, tail) \
+			((int)((char *)(head) - (char *)(tail)))
+
 /**
  * lws_snprintf(): snprintf that truncates the returned length too
  *
diff --git a/lib/misc/lws-ring.c b/lib/misc/lws-ring.c
index 60fc7cbe..c0fbe6dd 100644
--- a/lib/misc/lws-ring.c
+++ b/lib/misc/lws-ring.c
@@ -30,8 +30,8 @@ lws_ring_create(size_t element_len, size_t count,
 	if (!ring)
 		return NULL;
 
-	ring->buflen = count * element_len;
-	ring->element_len = element_len;
+	ring->buflen = (uint32_t)(count * element_len);
+	ring->element_len = (uint32_t)element_len;
 	ring->head = 0;
 	ring->oldest_tail = 0;
 	ring->destroy_element = destroy_element;
@@ -126,7 +126,7 @@ lws_ring_next_linear_insert_range(struct lws_ring *ring, void **start,
 	int n;
 
 	/* n is how many bytes the whole fifo can take */
-	n = lws_ring_get_count_free_elements(ring) * ring->element_len;
+	n = (int)(lws_ring_get_count_free_elements(ring) * ring->element_len);
 
 	if (!n)
 		return 1;
@@ -147,7 +147,7 @@ lws_ring_next_linear_insert_range(struct lws_ring *ring, void **start,
 LWS_VISIBLE LWS_EXTERN void
 lws_ring_bump_head(struct lws_ring *ring, size_t bytes)
 {
-	ring->head = (ring->head + bytes) % ring->buflen;
+	ring->head = (ring->head + (uint32_t)bytes) % ring->buflen;
 }
 
 LWS_VISIBLE LWS_EXTERN size_t
@@ -157,11 +157,11 @@ lws_ring_insert(struct lws_ring *ring, const void *src, size_t max_count)
 	int m, n;
 
 	/* n is how many bytes the whole fifo can take */
-	n = lws_ring_get_count_free_elements(ring) * ring->element_len;
+	n = (int)(lws_ring_get_count_free_elements(ring) * ring->element_len);
 
 	/* restrict n to how much we want to insert */
-	if ((size_t)n > max_count * ring->element_len)
-		n = max_count * ring->element_len;
+	if ((uint32_t)n > max_count * ring->element_len)
+		n = (int)(max_count * ring->element_len);
 
 	/*
 	 * n is legal to insert, but as an optimization we can cut the
@@ -206,11 +206,11 @@ lws_ring_consume(struct lws_ring *ring, uint32_t *tail, void *dest,
 	}
 
 	/* n is how many bytes the whole fifo has for us */
-	n = lws_ring_get_count_waiting_elements(ring, tail) * ring->element_len;
+	n = (int)(lws_ring_get_count_waiting_elements(ring, tail) * ring->element_len);
 
 	/* restrict n to how much we want to insert */
 	if ((size_t)n > max_count * ring->element_len)
-		n = max_count * ring->element_len;
+		n = (int)(max_count * ring->element_len);
 
 	if (!dest) {
 		*tail = ((*tail) + n) % ring->buflen;
diff --git a/lib/output.c b/lib/output.c
index c7d9d8e3..411a1d40 100644
--- a/lib/output.c
+++ b/lib/output.c
@@ -64,7 +64,7 @@ int lws_issue_raw(struct lws *wsi, unsigned char *buf, size_t len)
 	/* just ignore sends after we cleared the truncation buffer */
 	if (wsi->state == LWSS_FLUSHING_STORED_SEND_BEFORE_CLOSE &&
 	    !wsi->trunc_len)
-		return len;
+		return (int)len;
 
 	if (wsi->trunc_len && (buf < wsi->trunc_alloc ||
 	    buf > (wsi->trunc_alloc + wsi->trunc_len + wsi->trunc_offset))) {
@@ -85,7 +85,7 @@ int lws_issue_raw(struct lws *wsi, unsigned char *buf, size_t len)
 		return -1;
 	}
 
-	m = lws_ext_cb_active(wsi, LWS_EXT_CB_PACKET_TX_DO_SEND, &buf, len);
+	m = lws_ext_cb_active(wsi, LWS_EXT_CB_PACKET_TX_DO_SEND, &buf, (int)len);
 	if (m < 0)
 		return -1;
 	if (m) /* handled */ {
@@ -98,15 +98,15 @@ int lws_issue_raw(struct lws *wsi, unsigned char *buf, size_t len)
 
 	/* limit sending */
 	if (wsi->protocol->tx_packet_size)
-		n = wsi->protocol->tx_packet_size;
+		n = (int)wsi->protocol->tx_packet_size;
 	else {
-		n = wsi->protocol->rx_buffer_size;
+		n = (int)wsi->protocol->rx_buffer_size;
 		if (!n)
 			n = context->pt_serv_buf_size;
 	}
 	n += LWS_PRE + 4;
 	if (n > len)
-		n = len;
+		n = (int)len;
 #if defined(LWS_WITH_ESP8266)	
 	if (wsi->pending_send_completion) {
 		n = 0;
@@ -142,7 +142,7 @@ handle_truncated_send:
 		if (!wsi->trunc_len) {
 			lwsl_info("***** %p partial send completed\n", wsi);
 			/* done with it, but don't free it */
-			n = real_len;
+			n = (int)real_len;
 			if (wsi->state == LWSS_FLUSHING_STORED_SEND_BEFORE_CLOSE) {
 				lwsl_info("***** %p signalling to close now\n", wsi);
 				return -1; /* retry closing now */
@@ -176,7 +176,7 @@ handle_truncated_send:
 	if (!wsi->trunc_alloc || real_len - n > wsi->trunc_alloc_len) {
 		lws_free(wsi->trunc_alloc);
 
-		wsi->trunc_alloc_len = real_len - n;
+		wsi->trunc_alloc_len = (unsigned int)(real_len - n);
 		wsi->trunc_alloc = lws_malloc(real_len - n, "truncated send alloc");
 		if (!wsi->trunc_alloc) {
 			lwsl_err("truncated send: unable to malloc %lu\n",
@@ -185,13 +185,13 @@ handle_truncated_send:
 		}
 	}
 	wsi->trunc_offset = 0;
-	wsi->trunc_len = real_len - n;
+	wsi->trunc_len = (unsigned int)(real_len - n);
 	memcpy(wsi->trunc_alloc, buf + n, real_len - n);
 
 	/* since something buffered, force it to get another chance to send */
 	lws_callback_on_writable(wsi);
 
-	return real_len;
+	return (int)real_len;
 }
 
 LWS_VISIBLE int lws_write(struct lws *wsi, unsigned char *buf, size_t len,
@@ -219,7 +219,7 @@ LWS_VISIBLE int lws_write(struct lws *wsi, unsigned char *buf, size_t len,
 				(void *)&pas, 0))
 			return 1;
 
-		return len;
+		return (int)len;
 	}
 
 	lws_stats_atomic_bump(wsi->context, pt, LWSSTATS_C_API_LWS_WRITE, 1);
@@ -297,7 +297,7 @@ LWS_VISIBLE int lws_write(struct lws *wsi, unsigned char *buf, size_t len,
 	 * interleaving of control frames and other connection service.
 	 */
 	eff_buf.token = (char *)buf;
-	eff_buf.token_len = len;
+	eff_buf.token_len = (int)len;
 
 	switch ((int)wp) {
 	case LWS_WRITE_PING:
@@ -353,7 +353,7 @@ LWS_VISIBLE int lws_write(struct lws *wsi, unsigned char *buf, size_t len,
 			if (!wsi->u.ws.stashed_write_pending)
 				wsi->u.ws.stashed_write_type = (char)wp & 0x3f;
 			wsi->u.ws.stashed_write_pending = 1;
-			return len;
+			return (int)len;
 		}
 		/*
 		 * extension recreated it:
@@ -523,7 +523,7 @@ send_raw:
 			}
 
 			return lws_h2_frame_write(wsi, n, flags,
-					wsi->u.h2.my_sid, len, buf);
+					wsi->u.h2.my_sid, (int)len, buf);
 		}
 #endif
 		return lws_issue_raw(wsi, (unsigned char *)buf - pre, len + pre);
@@ -558,7 +558,7 @@ send_raw:
 	if (n == (int)len + pre) {
 		/* everything in the buffer was handled (or rebuffered...) */
 		wsi->u.ws.inside_frame = 0;
-		return orig_len;
+		return (int)orig_len;
 	}
 
 	/*
@@ -685,7 +685,7 @@ LWS_VISIBLE int lws_serve_http_file_fragment(struct lws *wsi)
 		if (wsi->sending_chunked)
 			n = (int)amount;
 		else
-			n = (p - pstart) + (int)amount;
+			n = lws_ptr_diff(p, pstart) + (int)amount;
 
 		lwsl_debug("%s: sending %d\n", __func__, n);
 
diff --git a/lib/plat/lws-plat-win.c b/lib/plat/lws-plat-win.c
index 8f1ecf75..7cbb7df7 100644
--- a/lib/plat/lws-plat-win.c
+++ b/lib/plat/lws-plat-win.c
@@ -148,7 +148,7 @@ lws_poll_listen_fd(struct lws_pollfd *fd)
 	FD_ZERO(&readfds);
 	FD_SET(fd->fd, &readfds);
 
-	return select(fd->fd + 1, &readfds, NULL, NULL, &tv);
+	return select(((int)fd->fd) + 1, &readfds, NULL, NULL, &tv);
 }
 
 LWS_VISIBLE void
@@ -428,7 +428,7 @@ lws_interface_to_sa(int ipv6,
 	if (address == INADDR_NONE)
 		return -1;
 
-	addr->sin_addr.s_addr = (lws_intptr_t)address;
+	addr->sin_addr.s_addr = (unsigned long)(lws_intptr_t)address;
 
 	return 0;
 }
@@ -548,7 +548,7 @@ LWS_VISIBLE int
 lws_plat_inet_pton(int af, const char *src, void *dst)
 {
 	WCHAR *buffer;
-	DWORD bufferlen = strlen(src) + 1;
+	DWORD bufferlen = (int)strlen(src) + 1;
 	BOOL ok = FALSE;
 
 	buffer = lws_malloc(bufferlen * 2, "inet_pton");
diff --git a/lib/private-libwebsockets.h b/lib/private-libwebsockets.h
index 1a5b25f7..7e1df5c6 100644
--- a/lib/private-libwebsockets.h
+++ b/lib/private-libwebsockets.h
@@ -733,8 +733,8 @@ enum {
 struct lws_ring {
 	void *buf;
 	void (*destroy_element)(void *element);
-	size_t buflen;
-	size_t element_len;
+	uint32_t buflen;
+	uint32_t element_len;
 	uint32_t head;
 	uint32_t oldest_tail;
 };
diff --git a/lib/server/fops-zip.c b/lib/server/fops-zip.c
index 1f0bf416..8b68ce21 100644
--- a/lib/server/fops-zip.c
+++ b/lib/server/fops-zip.c
@@ -348,7 +348,7 @@ lws_fops_zip_open(const struct lws_plat_file_ops *fops, const char *vfs_path,
 
 	m = sizeof(rp) - 1;
 	if ((vpath - vfs_path - 1) < m)
-		m = vpath - vfs_path - 1;
+		m = lws_ptr_diff(vpath, vfs_path) - 1;
 	strncpy(rp, vfs_path, m);
 	rp[m] = '\0';
 
@@ -363,7 +363,7 @@ lws_fops_zip_open(const struct lws_plat_file_ops *fops, const char *vfs_path,
 	if (*vpath == '/')
 		vpath++;
 
-	m = lws_fops_zip_scan(priv, vpath, strlen(vpath));
+	m = lws_fops_zip_scan(priv, vpath, (int)strlen(vpath));
 	if (m) {
 		lwsl_err("unable to find record matching '%s' %d\n", vpath, m);
 		goto bail2;
diff --git a/lib/server/parsers.c b/lib/server/parsers.c
index b75740c6..872fda0d 100644
--- a/lib/server/parsers.c
+++ b/lib/server/parsers.c
@@ -1733,18 +1733,18 @@ lws_payload_until_length_exhausted(struct lws *wsi, unsigned char **buf,
 	char *rx_ubuf;
 
 	if (wsi->protocol->rx_buffer_size)
-		buffer_size = wsi->protocol->rx_buffer_size;
+		buffer_size = (int)wsi->protocol->rx_buffer_size;
 	else
 		buffer_size = wsi->context->pt_serv_buf_size;
 	avail = buffer_size - wsi->u.ws.rx_ubuf_head;
 
 	/* do not consume more than we should */
 	if (avail > wsi->u.ws.rx_packet_length)
-		avail = wsi->u.ws.rx_packet_length;
+		avail = (unsigned int)wsi->u.ws.rx_packet_length;
 
 	/* do not consume more than what is in the buffer */
 	if (avail > *len)
-		avail = *len;
+		avail = (unsigned int)(*len);
 
 	/* we want to leave 1 byte for the parser to handle properly */
 	if (avail <= 1)
diff --git a/lib/server/server-handshake.c b/lib/server/server-handshake.c
index ba471b29..8f2b77a9 100644
--- a/lib/server/server-handshake.c
+++ b/lib/server/server-handshake.c
@@ -190,7 +190,7 @@ lws_extension_server_handshake(struct lws *wsi, char **p, int budget)
 					    !strncmp(args, po->name,
 							    strlen(po->name))) {
 						oa.option_name = NULL;
-						oa.option_index = po - opts;
+						oa.option_index = (int)(po - opts);
 						oa.start = NULL;
 						lwsl_debug("setting %s\n", po->name);
 						if (!ext->callback(
@@ -303,7 +303,8 @@ handshake_0405(struct lws_context *context, struct lws *wsi)
 	LWS_CPYAPP(p, "\x0d\x0a");
 
 	args.p = p;
-	args.max_len = ((char *)pt->serv_buf + context->pt_serv_buf_size) - p;
+	args.max_len = lws_ptr_diff((char *)pt->serv_buf +
+				    context->pt_serv_buf_size, p);
 	if (user_callback_handle_rxflow(wsi->protocol->callback, wsi,
 					LWS_CALLBACK_ADD_HEADERS,
 					wsi->user_space, &args, 0))
@@ -320,7 +321,7 @@ handshake_0405(struct lws_context *context, struct lws *wsi)
 
 		/* okay send the handshake response accepting the connection */
 
-		lwsl_parser("issuing resp pkt %d len\n", (int)(p - response));
+		lwsl_parser("issuing resp pkt %d len\n", lws_ptr_diff(p, response));
 #if defined(DEBUG) && ! defined(LWS_WITH_ESP8266)
 		fwrite(response, 1,  p - response, stderr);
 #endif
diff --git a/lib/server/server.c b/lib/server/server.c
index dd0ec645..997a6008 100644
--- a/lib/server/server.c
+++ b/lib/server/server.c
@@ -240,11 +240,11 @@ lws_select_vhost(struct lws_context *context, int port, const char *servername)
 	const char *p;
 	int n, m, colon;
 
-	n = strlen(servername);
+	n = (int)strlen(servername);
 	colon = n;
 	p = strchr(servername, ':');
 	if (p)
-		colon = p - servername;
+		colon = lws_ptr_diff(p, servername);
 
 	/* Priotity 1: first try exact matches */
 
@@ -266,7 +266,7 @@ lws_select_vhost(struct lws_context *context, int port, const char *servername)
 	 */
 	vhost = context->vhost_list;
 	while (vhost) {
-		m = strlen(vhost->name);
+		m = (int)strlen(vhost->name);
 		if (port == vhost->listen_port &&
 		    m <= (colon - 2) &&
 		    servername[colon - m - 1] == '.' &&
@@ -298,7 +298,7 @@ lws_select_vhost(struct lws_context *context, int port, const char *servername)
 LWS_VISIBLE LWS_EXTERN const char *
 lws_get_mimetype(const char *file, const struct lws_http_mount *m)
 {
-	int n = strlen(file);
+	int n = (int)strlen(file);
 	const struct lws_protocol_vhost_options *pvo = NULL;
 
 	if (m)
@@ -549,7 +549,7 @@ lws_http_serve(struct lws *wsi, char *uri, const char *origin,
 	 * a protocol
 	 */
 	while (pvo) {
-		n = strlen(path);
+		n = (int)strlen(path);
 		if (n > (int)strlen(pvo->name) &&
 		    !strcmp(&path[n - strlen(pvo->name)], pvo->name)) {
 			wsi->sending_chunked = 1;
@@ -574,14 +574,15 @@ lws_http_serve(struct lws *wsi, char *uri, const char *origin,
 		if (lws_bind_protocol(wsi, pp))
 			return 1;
 		args.p = (char *)p;
-		args.max_len = end - p;
+		args.max_len = lws_ptr_diff(end, p);
 		if (pp->callback(wsi, LWS_CALLBACK_ADD_HEADERS,
 					  wsi->user_space, &args, 0))
 			return -1;
 		p = (unsigned char *)args.p;
 	}
 
-	n = lws_serve_http_file(wsi, path, mimetype, (char *)start, p - start);
+	n = lws_serve_http_file(wsi, path, mimetype, (char *)start,
+				lws_ptr_diff(p, start));
 
 	if (n < 0 || ((n > 0) && lws_http_transaction_completed(wsi)))
 		return -1; /* error or can't reuse connection: close the socket */
@@ -1195,7 +1196,7 @@ lws_http_action(struct lws *wsi)
 	}
 #endif
 
-	n = strlen(s);
+	n = (int)strlen(s);
 	if (s[0] == '\0' || (n == 1 && s[n - 1] == '/'))
 		s = (char *)hit->def;
 	if (!s)
@@ -1290,7 +1291,7 @@ lws_server_init_wsi_for_ws(struct lws *wsi)
 	 * a big default for compatibility
 	 */
 
-	n = wsi->protocol->rx_buffer_size;
+	n = (int)wsi->protocol->rx_buffer_size;
 	if (!n)
 		n = wsi->context->pt_serv_buf_size;
 	n += LWS_PRE;
@@ -2204,7 +2205,7 @@ adopt_socket_readbuf(struct lws *wsi, const char *readbuf, size_t len)
 		goto bail;
 	}
 	memcpy(wsi->u.hdr.preamble_rx, readbuf, len);
-	wsi->u.hdr.preamble_rx_len = len;
+	wsi->u.hdr.preamble_rx_len = (int)len;
 
 	return wsi;
 
@@ -2548,9 +2549,9 @@ try_pollout:
 			 * we could, not accepting it due to PEER_LIMITS would
 			 * block the connect queue for other legit peers.
 			 */
-			accept_fd  = accept(pollfd->fd, (struct sockaddr *)&cli_addr,
+			accept_fd  = accept((int)pollfd->fd, (struct sockaddr *)&cli_addr,
 					    &clilen);
-			lws_latency(context, wsi, "listener accept", accept_fd,
+			lws_latency(context, wsi, "listener accept", (int)accept_fd,
 				    accept_fd >= 0);
 			if (accept_fd < 0) {
 				if (LWS_ERRNO == LWS_EAGAIN ||
@@ -2712,7 +2713,7 @@ lws_serve_http_file(struct lws *wsi, const char *file, const char *content_type,
 	    content_type && content_type[0])
 		if (lws_add_http_header_by_token(wsi, WSI_TOKEN_HTTP_CONTENT_TYPE,
 						 (unsigned char *)content_type,
-						 strlen(content_type), &p, end))
+						 (int)strlen(content_type), &p, end))
 			return -1;
 
 #if defined(LWS_WITH_RANGES)
@@ -2855,7 +2856,7 @@ lws_interpret_incoming_packet(struct lws *wsi, unsigned char **buf, size_t len)
 		 * we were accepting input but now we stopped doing so
 		 */
 		if (wsi->rxflow_bitmap) {
-			lws_rxflow_cache(wsi, *buf, 0, len);
+			lws_rxflow_cache(wsi, *buf, 0, (int)len);
 			lwsl_parser("%s: cached %ld\n", __func__, (long)len);
 			return 1;
 		}
@@ -2972,7 +2973,7 @@ skip:
 				pc = s->replace(s->data, hit);
 				if (!pc)
 					pc = "NULL";
-				n = strlen(pc);
+				n = (int)strlen(pc);
 				s->swallow[s->pos] = '\0';
 				if (n != s->pos) {
 					memmove(s->start + n,
diff --git a/lib/service.c b/lib/service.c
index fa1cc8bd..1b9c2adf 100644
--- a/lib/service.c
+++ b/lib/service.c
@@ -633,7 +633,7 @@ int lws_rxflow_cache(struct lws *wsi, unsigned char *buf, int n, int len)
 		assert ((char *)buf >= (char *)h2n->rx_scratch &&
 			(char *)&buf[len] <= (char *)&h2n->rx_scratch[LWS_H2_RX_SCRATCH_SIZE]);
 
-		h2n->rx_scratch_pos = ((char *)buf - (char *)h2n->rx_scratch);
+		h2n->rx_scratch_pos = lws_ptr_diff(buf, h2n->rx_scratch);
 		h2n->rx_scratch_len = len;
 
 		lwsl_info("%s: %p: pausing h2 rx_scratch\n", __func__, wsi);
@@ -1227,6 +1227,7 @@ lws_service_fd_tsi(struct lws_context *context, struct lws_pollfd *pollfd, int t
 	case LWSCM_EVENT_PIPE:
 	{
 		struct lws_vhost *v = context->vhost_list;
+#if !defined(WIN32) && !defined(_WIN32)
 		char s[10];
 
 		/*
@@ -1238,6 +1239,7 @@ lws_service_fd_tsi(struct lws_context *context, struct lws_pollfd *pollfd, int t
 		(void)n;
 		if (n < 0)
 			goto close_and_handled;
+#endif
 
 		/*
 		 * the poll() wait, or the event loop for libuv etc is a
diff --git a/lib/tls/openssl/client.c b/lib/tls/openssl/client.c
index 1eb9f19b..50a280d2 100644
--- a/lib/tls/openssl/client.c
+++ b/lib/tls/openssl/client.c
@@ -184,7 +184,7 @@ lws_ssl_client_bio_create(struct lws *wsi)
 #endif
 #endif /* USE_WOLFSSL */
 
-	wsi->client_bio = BIO_new_socket(wsi->desc.sockfd, BIO_NOCLOSE);
+	wsi->client_bio = BIO_new_socket((int)(long long)wsi->desc.sockfd, BIO_NOCLOSE);
 	SSL_set_bio(wsi->ssl, wsi->client_bio, wsi->client_bio);
 
 #ifdef USE_WOLFSSL
diff --git a/lib/tls/openssl/lws-genhash.c b/lib/tls/openssl/lws-genhash.c
index df2ce46c..c81aca3d 100644
--- a/lib/tls/openssl/lws-genhash.c
+++ b/lib/tls/openssl/lws-genhash.c
@@ -146,7 +146,7 @@ lws_genhmac_init(struct lws_genhmac_ctx *ctx, enum lws_genhmac_types type,
         if (EVP_DigestInit_ex(ctx->ctx, md, NULL) != 1)
 		return -1;
 
-        pkey = EVP_PKEY_new_mac_key(EVP_PKEY_HMAC, NULL, key, key_len);
+        pkey = EVP_PKEY_new_mac_key(EVP_PKEY_HMAC, NULL, key, (int)key_len);
 
         if (EVP_DigestSignInit(ctx->ctx, NULL, md, NULL, pkey) != 1)
 		return -1;
diff --git a/lib/tls/openssl/lws-genrsa.c b/lib/tls/openssl/lws-genrsa.c
index 6bdcde48..b86068e2 100644
--- a/lib/tls/openssl/lws-genrsa.c
+++ b/lib/tls/openssl/lws-genrsa.c
@@ -163,11 +163,11 @@ cleanup_1:
 
 LWS_VISIBLE int
 lws_genrsa_public_decrypt(struct lws_genrsa_ctx *ctx, const uint8_t *in,
-			   size_t in_len, uint8_t *out, size_t out_max)
+			  size_t in_len, uint8_t *out, size_t out_max)
 {
 	uint32_t m;
 
-	m = RSA_public_decrypt(in_len, in, out, ctx->rsa, RSA_PKCS1_PADDING);
+	m = RSA_public_decrypt((int)in_len, in, out, ctx->rsa, RSA_PKCS1_PADDING);
 
 	/* the bignums are also freed by freeing the RSA */
 	RSA_free(ctx->rsa);
@@ -208,12 +208,12 @@ lws_genrsa_public_verify(struct lws_genrsa_ctx *ctx, const uint8_t *in,
 			 size_t sig_len)
 {
 	int n = lws_genrsa_genrsa_hash_to_NID(hash_type),
-	    h = lws_genhash_size(hash_type);
+	    h = (int)lws_genhash_size(hash_type);
 
 	if (n < 0)
 		return -1;
 
-	n = RSA_verify(n, in, h, (uint8_t *)sig, sig_len, ctx->rsa);
+	n = RSA_verify(n, in, h, (uint8_t *)sig, (int)sig_len, ctx->rsa);
 	if (n != 1) {
 		lwsl_notice("%s: -0x%x\n", __func__, -n);
 
@@ -229,7 +229,7 @@ lws_genrsa_public_sign(struct lws_genrsa_ctx *ctx, const uint8_t *in,
 			 size_t sig_len)
 {
 	int n = lws_genrsa_genrsa_hash_to_NID(hash_type),
-	    h = lws_genhash_size(hash_type);
+	    h = (int)lws_genhash_size(hash_type);
 	unsigned int used = 0;
 
 	if (n < 0)
diff --git a/lib/tls/openssl/server.c b/lib/tls/openssl/server.c
index 2a5032fa..729abfcd 100644
--- a/lib/tls/openssl/server.c
+++ b/lib/tls/openssl/server.c
@@ -340,7 +340,7 @@ lws_tls_server_new_nonblocking(struct lws *wsi, lws_sockfd_type accept_fd)
 	}
 
 	SSL_set_ex_data(wsi->ssl, openssl_websocket_private_data_index, wsi);
-	SSL_set_fd(wsi->ssl, accept_fd);
+	SSL_set_fd(wsi->ssl, (int)(long long)accept_fd);
 
 #ifdef USE_WOLFSSL
 #ifdef USE_OLD_CYASSL
diff --git a/lib/tls/openssl/ssl.c b/lib/tls/openssl/ssl.c
index 5b46809d..7da354fe 100644
--- a/lib/tls/openssl/ssl.c
+++ b/lib/tls/openssl/ssl.c
@@ -103,7 +103,7 @@ lws_context_init_ssl_pem_passwd_cb(char * buf, int size, int rwflag,
 	strncpy(buf, info->ssl_private_key_password, size);
 	buf[size - 1] = '\0';
 
-	return strlen(buf);
+	return (int)strlen(buf);
 }
 
 void
diff --git a/plugins/generic-table/protocol_table_dirlisting.c b/plugins/generic-table/protocol_table_dirlisting.c
index f8787980..dd1300a2 100644
--- a/plugins/generic-table/protocol_table_dirlisting.c
+++ b/plugins/generic-table/protocol_table_dirlisting.c
@@ -262,7 +262,7 @@ callback_lws_table_dirlisting(struct lws *wsi, enum lws_callback_reasons reason,
 				s1[0] = '\0';
 				q += strlen(q);
 			} else {
-				n = q1 - q;
+				n = lws_ptr_diff(q1, q);
 				if (n > (int)sizeof(s) - 1)
 					n = sizeof(s) - 1;
 				if (first) {
@@ -272,7 +272,7 @@ callback_lws_table_dirlisting(struct lws *wsi, enum lws_callback_reasons reason,
 					strncpy(s, q, n);
 					s[n] = '\0';
 
-					n = q1 - pss->reldir;
+					n = lws_ptr_diff(q1, pss->reldir);
 					if (n > (int)sizeof(s1) - 1)
 						n = sizeof(s1) - 1;
 					strncpy(s1, pss->reldir, n);
diff --git a/plugins/protocol_lws_meta.c b/plugins/protocol_lws_meta.c
index 4944cff1..69324db0 100644
--- a/plugins/protocol_lws_meta.c
+++ b/plugins/protocol_lws_meta.c
@@ -112,7 +112,7 @@ lws_get_channel_wsi(struct per_session_data__lws_meta *pss, int ch)
 static int
 lws_get_channel_id(struct lws *wsi)
 {
-	return (lws_intptr_t)lws_get_opaque_parent_data(wsi);
+	return (int)(lws_intptr_t)lws_get_opaque_parent_data(wsi);
 }
 
 static void
diff --git a/plugins/protocol_lws_mirror.c b/plugins/protocol_lws_mirror.c
index 8affca99..80b11d7f 100644
--- a/plugins/protocol_lws_mirror.c
+++ b/plugins/protocol_lws_mirror.c
@@ -108,7 +108,8 @@ mirror_update_worst_tail(struct mirror_instance *mi)
 
 	lws_start_foreach_ll(struct per_session_data__lws_mirror *,
 			     pss, mi->same_mi_pss_list) {
-		wai = lws_ring_get_count_waiting_elements(mi->ring, &pss->tail);
+		wai = (uint32_t)lws_ring_get_count_waiting_elements(mi->ring,
+								&pss->tail);
 		if (wai >= worst) {
 			worst = wai;
 			worst_tail = pss->tail;
@@ -370,7 +371,7 @@ callback_lws_mirror(struct lws *wsi, enum lws_callback_reasons reason,
 		break;
 
 	case LWS_CALLBACK_RECEIVE:
-		n = lws_ring_get_count_free_elements(pss->mi->ring);
+		n = (int)lws_ring_get_count_free_elements(pss->mi->ring);
 		if (!n) {
 			lwsl_notice("dropping!\n");
 			if (pss->mi->rx_enabled)
diff --git a/plugins/protocol_lws_sshd_demo.c b/plugins/protocol_lws_sshd_demo.c
index 47f7471e..ca2fe3eb 100644
--- a/plugins/protocol_lws_sshd_demo.c
+++ b/plugins/protocol_lws_sshd_demo.c
@@ -102,7 +102,7 @@ enter_state(struct sshd_instance_priv *priv, enum states state)
 	priv->state = state;
 	priv->ptr = strings[state];
 	priv->pos = 0;
-	priv->len = strlen(priv->ptr);
+	priv->len = (int)strlen(priv->ptr);
 
 	lws_callback_on_writable(priv->wsi);
 }
@@ -168,7 +168,7 @@ ssh_ops_tx(void *_priv, int stdch, uint8_t *buf, size_t len)
 		return 0;
 
 	memcpy(buf, priv->ptr + priv->pos, chunk);
-	priv->pos += chunk;
+	priv->pos += (int)chunk;
 
 	if (priv->state == SSH_TEST_DONE && priv->pos == priv->len) {
 		/*
@@ -208,7 +208,7 @@ ssh_ops_get_server_key(struct lws *wsi, uint8_t *buf, size_t len)
 	int n;
 
 	lseek(vhd->privileged_fd, 0, SEEK_SET);
-	n = read(vhd->privileged_fd, buf, len);
+	n = read(vhd->privileged_fd, buf, (int)len);
 	if (n < 0) {
 		lwsl_err("%s: read failed: %d\n", __func__, n);
 		n = 0;
@@ -226,7 +226,7 @@ ssh_ops_set_server_key(struct lws *wsi, uint8_t *buf, size_t len)
 						 lws_get_protocol(wsi));
 	int n;
 
-	n = write(vhd->privileged_fd, buf, len);
+	n = write(vhd->privileged_fd, buf, (int)len);
 	if (n < 0) {
 		lwsl_err("%s: read failed: %d\n", __func__, errno);
 		n = 0;
@@ -242,7 +242,7 @@ ssh_ops_is_pubkey_authorized(const char *username, const char *type,
 				 const uint8_t *peer, int peer_len)
 {
 	char *aps = NULL, *p, *ps;
-	int n = strlen(type), alen = 2048, ret = 2, len;
+	int n = (int)strlen(type), alen = 2048, ret = 2, len;
 	size_t s = 0;
 
 	lwsl_info("%s: checking pubkey for %s\n", __func__, username);
diff --git a/plugins/protocol_post_demo.c b/plugins/protocol_post_demo.c
index b5d5e828..434901ec 100644
--- a/plugins/protocol_post_demo.c
+++ b/plugins/protocol_post_demo.c
@@ -77,7 +77,7 @@ file_upload_cb(void *data, const char *name, const char *filename,
 		 * simple demo use a fixed name so we don't have to deal with
 		 * attacks  */
 #if !defined(LWS_WITH_ESP8266) && !defined(LWS_WITH_ESP32)
-		pss->fd = (lws_filefd_type)open("/tmp/post-file",
+		pss->fd = (lws_filefd_type)(long long)open("/tmp/post-file",
 			       O_CREAT | O_TRUNC | O_RDWR, 0600);
 #endif
 		break;
@@ -91,7 +91,7 @@ file_upload_cb(void *data, const char *name, const char *filename,
 				return 1;
 
 #if !defined(LWS_WITH_ESP8266) && !defined(LWS_WITH_ESP32)
-			n = write((int)pss->fd, buf, len);
+			n = write((int)(long long)pss->fd, buf, len);
 			lwsl_notice("%s: write %d says %d\n", __func__, len, n);
 #else
 			lwsl_notice("%s: Received chunk size %d\n", __func__, len);
@@ -100,7 +100,7 @@ file_upload_cb(void *data, const char *name, const char *filename,
 		if (state == LWS_UFS_CONTENT)
 			break;
 #if !defined(LWS_WITH_ESP8266) && !defined(LWS_WITH_ESP32)
-		close((int)pss->fd);
+		close((int)(long long)pss->fd);
 		pss->fd = LWS_INVALID_FILE;
 #endif
 		break;
@@ -134,7 +134,7 @@ callback_post_demo(struct lws *wsi, enum lws_callback_reasons reason,
 		}
 
 		/* let it parse the POST data */
-		if (lws_spa_process(pss->spa, in, len))
+		if (lws_spa_process(pss->spa, in, (int)len))
 			return -1;
 		break;
 
@@ -160,7 +160,7 @@ callback_post_demo(struct lws *wsi, enum lws_callback_reasons reason,
 				pss->filename, pss->file_length);
 
 		p += lws_snprintf((char *)p, end - p, "</body></html>");
-		pss->result_len = p - (unsigned char *)(pss->result + LWS_PRE);
+		pss->result_len = lws_ptr_diff(p, pss->result + LWS_PRE);
 
 		n = LWS_PRE + 1024;
 		buffer = malloc(n);
diff --git a/plugins/ssh-base/kex-25519.c b/plugins/ssh-base/kex-25519.c
index 3e9eaa7d..526125f3 100644
--- a/plugins/ssh-base/kex-25519.c
+++ b/plugins/ssh-base/kex-25519.c
@@ -109,7 +109,7 @@ lws_mpint_rfc4251(uint8_t *dest, const uint8_t *src, int bytes, int uns)
 	while (bytes--)
 		*dest++ = *src++;
 
-	return dest - odest;
+	return lws_ptr_diff(dest, odest);
 }
 
 int
@@ -154,7 +154,7 @@ ed25519_key_parse(uint8_t *p, size_t len, char *type, size_t type_len,
 		return 8;
 	m = l;
 	if (m > type_len)
-		m = type_len -1 ;
+		m = (uint32_t)type_len -1 ;
 	strncpy(type, (const char *)p, m);
 	type[m] = '\0';
 
@@ -198,7 +198,7 @@ _genhash_update_len(struct lws_genhash_ctx *ctx, const void *input, size_t ilen)
 {
 	uint32_t be;
 
-	lws_p32((uint8_t *)&be, ilen);
+	lws_p32((uint8_t *)&be, (uint32_t)ilen);
 
 	if (lws_genhash_update(ctx, (uint8_t *)&be, 4))
 		return 1;
@@ -315,7 +315,7 @@ kex_ecdh(struct per_session_data__sshd *pss, uint8_t *reply, uint32_t *plen)
 	char keyt[33];
 	int r, c;
 
-	r = get_gen_server_key_25519(pss, servkey, sizeof(servkey));
+	r = (int)get_gen_server_key_25519(pss, servkey, (int)sizeof(servkey));
 	if (!r) {
 		lwsl_err("%s: Failed to get or gen server key\n", __func__);
 
@@ -426,7 +426,7 @@ kex_ecdh(struct per_session_data__sshd *pss, uint8_t *reply, uint32_t *plen)
 	 * name length: name
 	 * key length: key
 	 * ---> */
-	lws_p32((uint8_t *)&be, 8 + strlen(keyt) + LWS_SIZE_EC25519);
+	lws_p32((uint8_t *)&be, 8 + (int)strlen(keyt) + LWS_SIZE_EC25519);
 	if (lws_genhash_update(&ctx, (void *)&be, 4))
 		goto hash_probs;
 
@@ -481,9 +481,9 @@ kex_ecdh(struct per_session_data__sshd *pss, uint8_t *reply, uint32_t *plen)
 
 	lp = p;
 	p +=4;
-	lws_sized_blob(&p, keyt, strlen(keyt));
+	lws_sized_blob(&p, keyt, (int)strlen(keyt));
 	lws_sized_blob(&p, pss->K_S, LWS_SIZE_EC25519);
-	lws_p32(lp, p - lp - 4);
+	lws_p32(lp, lws_ptr_diff(p, lp) - 4);
 
 	/* Q_S (exchange value sent by the server) */
 	
@@ -493,14 +493,14 @@ kex_ecdh(struct per_session_data__sshd *pss, uint8_t *reply, uint32_t *plen)
 
 	lp = p;
 	p +=4;
-	lws_sized_blob(&p, keyt, strlen(keyt));
+	lws_sized_blob(&p, keyt, (int)strlen(keyt));
 	lws_sized_blob(&p, payload_sig, 64);
-	lws_p32(lp, p - lp - 4);
+	lws_p32(lp, lws_ptr_diff(p, lp) - 4);
 
 	/* end of message */
 
 	lws_pad_set_length(pss, reply, &p, &pss->active_keys_stc);
-	*plen = p - reply;
+	*plen = lws_ptr_diff(p, reply);
 
 	if (!pss->active_keys_stc.valid)
 		memcpy(pss->session_id, temp, LWS_SIZE_EC25519);
diff --git a/plugins/ssh-base/sshd.c b/plugins/ssh-base/sshd.c
index a419cfef..c121178f 100644
--- a/plugins/ssh-base/sshd.c
+++ b/plugins/ssh-base/sshd.c
@@ -62,7 +62,7 @@ lws_p32(uint8_t *p, uint32_t v)
 int
 lws_cstr(uint8_t **p, const char *s, uint32_t max)
 {
-	uint32_t n = strlen(s);
+	uint32_t n = (uint32_t)strlen(s);
 
 	if (n > max)
 		return 1;
@@ -122,7 +122,7 @@ void
 lws_pad_set_length(struct per_session_data__sshd *pss, void *start, uint8_t **p,
 		   struct lws_ssh_keys *keys)
 {
-	uint32_t len = *p - (uint8_t *)start;
+	uint32_t len = lws_ptr_diff(*p, start);
 	uint8_t padc = 4, *bs = start;
 
 	if (keys->full_length)
@@ -157,7 +157,7 @@ offer(struct per_session_data__sshd *pss, uint8_t *p, uint32_t len, int first,
 	char keyt[32];
 	uint8_t keybuf[256];
 
-	keylen = get_gen_server_key_25519(pss, keybuf, sizeof(keybuf));
+	keylen = (int)get_gen_server_key_25519(pss, keybuf, (int)sizeof(keybuf));
 	if (!keylen) {
 		lwsl_notice("get_gen_server_key failed\n");
 		return 1;
@@ -281,7 +281,7 @@ offer(struct per_session_data__sshd *pss, uint8_t *p, uint32_t len, int first,
 	*p++ = 0;
 	*p++ = 0;
 
-	len = p - op;
+	len = lws_ptr_diff(p, op);
 	if (payload_len)
 		/* starts at buf + 5 and excludes padding */
 		*payload_len = len - 5;
@@ -317,7 +317,7 @@ handle_name(struct per_session_data__sshd *pss)
 			kex->match_bitfield |= 1;
 		break;
 	case SSH_KEX_NL_SHK_ALGS:
-		len = get_gen_server_key_25519(pss, keybuf, sizeof(keybuf));
+		len = (int)get_gen_server_key_25519(pss, keybuf, (int)sizeof(keybuf));
 		if (!len)
 			break;
 		if (ed25519_key_parse(keybuf, len,
@@ -1174,12 +1174,12 @@ again:
 			 */
 			n = 4 + 32 +
 			    1 +
-			    4 + strlen(pss->ua->username) +
-			    4 + strlen(pss->ua->service) +
+			    4 + (int)strlen(pss->ua->username) +
+			    4 + (int)strlen(pss->ua->service) +
 			    4 + 9 +
 			    1 +
-			    4 + strlen(pss->ua->alg) +
-			    4 + pss->ua->pubkey_len;
+			    4 + (int)strlen(pss->ua->alg) +
+			    4 + (int)pss->ua->pubkey_len;
 
 			ps = sshd_zalloc(n);
 			if (!ps) {
@@ -1854,7 +1854,7 @@ parse(struct per_session_data__sshd *pss, uint8_t *p, size_t len)
 			uint8_t pt[2048];
 
 			len++;
-			cp = len;
+			cp = (uint32_t)len;
 
 			if (cp > l - pss->pa_pos)
 				cp = l - pss->pa_pos;
@@ -1920,7 +1920,7 @@ pad_and_encrypt(uint8_t *dest, void *ps, uint8_t *pp,
 
 	if (!skip_pad)
 		lws_pad_set_length(pss, ps, &pp, &pss->active_keys_stc);
-	n = pp - (uint8_t *)ps;
+	n = lws_ptr_diff(pp, ps);
 
 	if (!pss->active_keys_stc.valid) {
 		memcpy(dest, ps, n);
@@ -2171,9 +2171,9 @@ lws_callback_raw_sshd(struct lws *wsi, enum lws_callback_reasons reason,
 			pp = ps + 5;
 			*pp++ = SSH_MSG_USERAUTH_BANNER;
 			if (pss->vhd && pss->vhd->ops->banner)
-				n = pss->vhd->ops->banner((char *)&buf[650],
+				n = (int)pss->vhd->ops->banner((char *)&buf[650],
 							  150 - 1,
-							  lang, sizeof(lang));
+							  lang, (int)sizeof(lang));
 			lws_p32(pp, n);
 			pp += 4;
 			strcpy((char *)pp, (char *)&buf[650]);
@@ -2362,12 +2362,12 @@ lws_callback_raw_sshd(struct lws *wsi, enum lws_callback_reasons reason,
 			pp += pss->vhd->ops->tx(ch->priv, n, pp,
 						&buf[sizeof(buf) - 1] - pp);
 
-			lws_p32(ps + m - 4, pp - (ps + m));
+			lws_p32(ps + m - 4, lws_ptr_diff(pp, (ps + m)));
 
 			if (pss->vhd->ops->tx_waiting(ch->priv) > 0)
 				lws_callback_on_writable(wsi);
 
-			ch->window -= (pp - ps) - m;
+			ch->window -= lws_ptr_diff(pp, ps) - m;
 			//lwsl_debug("our send window: %d\n", ch->window);
 
 			/* fallthru */
@@ -2465,7 +2465,7 @@ bail:
 	case LWS_CALLBACK_CGI_PROCESS_ATTACH:
 		ch = ssh_get_server_ch(pss, pss->channel_doing_spawn);
 		if (ch) {
-			ch->spawn_pid = len; /* child process PID */
+			ch->spawn_pid = (int)len; /* child process PID */
 			lwsl_notice("associated PID %d to ch %d\n", (int)len,
 				    pss->channel_doing_spawn);
 		}
diff --git a/plugins/ssh-base/telnet.c b/plugins/ssh-base/telnet.c
index 62d7a808..9d908fa2 100644
--- a/plugins/ssh-base/telnet.c
+++ b/plugins/ssh-base/telnet.c
@@ -202,8 +202,8 @@ lws_callback_raw_telnet(struct lws *wsi, enum lws_callback_reasons reason,
 			 * in the worst case of all 0xff, doubling the size
 			 */
 			pu = buf + LWS_PRE + 400;
-			m = pss->vhd->ops->tx(pss->priv, LWS_STDOUT, pu,
-					(sizeof(buf) - LWS_PRE - n - 401) / 2);
+			m = (int)pss->vhd->ops->tx(pss->priv, LWS_STDOUT, pu,
+					((int)sizeof(buf) - LWS_PRE - n - 401) / 2);
 
 			/*
 			 * apply telnet line discipline and copy into place
diff --git a/test-apps/test-fraggle.c b/test-apps/test-fraggle.c
index 1de73603..dd1e84e1 100644
--- a/test-apps/test-fraggle.c
+++ b/test-apps/test-fraggle.c
@@ -99,7 +99,7 @@ callback_fraggle(struct lws *wsi, enum lws_callback_reasons reason,
 			for (n = 0; (unsigned int)n < len; n++)
 				psf->sum += p[n];
 
-			psf->total_message += len;
+			psf->total_message += (int)len;
 			psf->packets_left++;
 
 			if (lws_is_final_fragment(wsi))
diff --git a/test-apps/test-server-http.c b/test-apps/test-server-http.c
index 3507d3c0..5ef640a1 100644
--- a/test-apps/test-server-http.c
+++ b/test-apps/test-server-http.c
@@ -95,7 +95,7 @@ dump_handshake_info(struct lws *wsi)
 
 const char * get_mimetype(const char *file)
 {
-	int n = strlen(file);
+	int n = (int)strlen(file);
 
 	if (n < 5)
 		return NULL;
@@ -149,7 +149,7 @@ file_upload_cb(void *data, const char *name, const char *filename,
 		/* we get the original filename in @filename arg, but for
 		 * simple demo use a fixed name so we don't have to deal with
 		 * attacks  */
-		pss->post_fd = (lws_filefd_type)open("/tmp/post-file",
+		pss->post_fd = (lws_filefd_type)(long long)open("/tmp/post-file",
 			       O_CREAT | O_TRUNC | O_RDWR, 0600);
 		break;
 	case LWS_UFS_FINAL_CONTENT:
@@ -161,12 +161,12 @@ file_upload_cb(void *data, const char *name, const char *filename,
 			if (pss->file_length > 100000)
 				return 1;
 
-			n = write((int)pss->post_fd, buf, len);
+			n = write((int)(long long)pss->post_fd, buf, len);
 			lwsl_notice("%s: write %d says %d\n", __func__, len, n);
 		}
 		if (state == LWS_UFS_CONTENT)
 			break;
-		close((int)pss->post_fd);
+		close((int)(long long)pss->post_fd);
 		pss->post_fd = LWS_INVALID_FILE;
 		break;
 	}
@@ -417,7 +417,7 @@ int callback_http(struct lws *wsi, enum lws_callback_reasons reason, void *user,
 							sizeof(leaf_path)))
 			return 1;
 #endif
-		n = (char *)p - leaf_path;
+		n = lws_ptr_diff(p, leaf_path);
 
 		n = lws_serve_http_file(wsi, buf, mimetype, other_headers, n);
 		if (n < 0)
@@ -450,7 +450,7 @@ int callback_http(struct lws *wsi, enum lws_callback_reasons reason, void *user,
 		}
 
 		/* let it parse the POST data */
-		if (lws_spa_process(pss->spa, in, len))
+		if (lws_spa_process(pss->spa, in, (int)len))
 			return -1;
 		break;
 
@@ -482,7 +482,7 @@ int callback_http(struct lws *wsi, enum lws_callback_reasons reason, void *user,
 				pss->filename, pss->file_length);
 
 		p += lws_snprintf((char *)p, end - p, "</body></html>");
-		pss->result_len = p - (unsigned char *)(pss->result + LWS_PRE);
+		pss->result_len = lws_ptr_diff(p, pss->result + LWS_PRE);
 
 		p = buffer + LWS_PRE;
 		start = p;
@@ -567,7 +567,7 @@ int callback_http(struct lws *wsi, enum lws_callback_reasons reason, void *user,
 			n = sizeof(buffer) - LWS_PRE;
 
 			/* but if the peer told us he wants less, we can adapt */
-			m = lws_get_peer_write_allowance(wsi);
+			m = (int)lws_get_peer_write_allowance(wsi);
 
 			/* -1 means not using a protocol that has this info */
 			if (m == 0)
@@ -712,7 +712,7 @@ bail:
 		 * called before any other POLL related callback
 		 * if protecting wsi lifecycle change, len == 1
 		 */
-		test_server_lock(len);
+		test_server_lock((int)len);
 		break;
 
 	case LWS_CALLBACK_UNLOCK_POLL:
@@ -721,7 +721,7 @@ bail:
 		 * called after any other POLL related callback
 		 * if protecting wsi lifecycle change, len == 1
 		 */
-		test_server_unlock(len);
+		test_server_unlock((int)len);
 		break;
 
 #ifdef EXTERNAL_POLL
diff --git a/win32port/win32helpers/getopt_long.c b/win32port/win32helpers/getopt_long.c
index 43a5cba7..22e5fa89 100644
--- a/win32port/win32helpers/getopt_long.c
+++ b/win32port/win32helpers/getopt_long.c
@@ -38,6 +38,9 @@
 #include <string.h>
 #include "getopt.h"
 
+#define lws_ptr_diff(head, tail) \
+			((int)((char *)(head) - (char *)(tail)))
+
 extern int	  opterr;	/* if error message should be printed */
 extern int	  optind;	/* index into parent argv vector */
 extern int	  optopt;	/* character checked for validity */
@@ -183,10 +186,10 @@ getopt_long(nargc, nargv, options, long_options, index)
 			return(-1);
 		}
 		if ((has_equal = strchr(current_argv, '=')) != NULL) {
-			current_argv_len = has_equal - current_argv;
+			current_argv_len = lws_ptr_diff(has_equal, current_argv);
 			has_equal++;
 		} else
-			current_argv_len = strlen(current_argv);
+			current_argv_len = (int)strlen(current_argv);
 
 		for (i = 0; long_options[i].name; i++) { 
 			if (strncmp(current_argv, long_options[i].name, current_argv_len))