diff --git a/lib/roles/cgi/cgi-server.c b/lib/roles/cgi/cgi-server.c
index c09416226..f9f954717 100644
--- a/lib/roles/cgi/cgi-server.c
+++ b/lib/roles/cgi/cgi-server.c
@@ -167,7 +167,7 @@ lws_cgi(struct lws *wsi, const char * const *exec_array,
 
 		if (m >= 0) {
 			env_array[n++] = p;
-			if (m < 8) {
+			if (m < (int)LWS_ARRAY_SIZE(meths) - 1) {
 				p += lws_snprintf(p, end - p,
 						  "REQUEST_METHOD=%s",
 						  meth_names[m]);
diff --git a/lib/roles/mqtt/mqtt.c b/lib/roles/mqtt/mqtt.c
index bb07feb53..8e2079de1 100644
--- a/lib/roles/mqtt/mqtt.c
+++ b/lib/roles/mqtt/mqtt.c
@@ -1760,7 +1760,10 @@ lws_mqtt_client_send_subcribe(struct lws *wsi, lws_mqtt_subscribe_param_t *sub)
 	lws_mqtt_str_t mqtt_vh_payload;
 	uint8_t exists[8], extant;
 	lws_mqtt_subs_t *mysub;
-	uint32_t rem_len, tops;
+	uint32_t rem_len;
+#if defined(_DEBUG)
+	uint32_t tops;
+#endif
 	uint32_t n;
 
 	assert(sub->num_topics);
@@ -1826,6 +1829,7 @@ lws_mqtt_client_send_subcribe(struct lws *wsi, lws_mqtt_subscribe_param_t *sub)
 			return 0;
 		}
 
+#if defined(_DEBUG)
 		/*
 		 * zero or more of the topics already existed, but not all,
 		 * so we must go to the server with a filtered list of the
@@ -1833,6 +1837,7 @@ lws_mqtt_client_send_subcribe(struct lws *wsi, lws_mqtt_subscribe_param_t *sub)
 		 */
 
 		tops = sub->num_topics - extant;
+#endif
 
 		/*
 		 * Pid + (Topic len field + Topic len + Req. QoS) x Num of Topics
@@ -1844,8 +1849,10 @@ lws_mqtt_client_send_subcribe(struct lws *wsi, lws_mqtt_subscribe_param_t *sub)
 
 		wsi->mqtt->sub_size = rem_len;
 
+#if defined(_DEBUG)
 		lwsl_debug("%s: Number of topics = %d, Remaining len = %d\n",
 			   __func__, (int)tops, (int)rem_len);
+#endif
 
 		p += lws_mqtt_vbi_encode(rem_len, p);
 
@@ -1933,8 +1940,11 @@ lws_mqtt_client_send_unsubcribe(struct lws *wsi,
 	struct lws *nwsi = lws_get_network_wsi(wsi);
 	lws_mqtt_str_t mqtt_vh_payload;
 	uint8_t send_unsub[8], orphaned;
-	uint32_t rem_len, n, tops;
+	uint32_t rem_len, n;
 	lws_mqtt_subs_t *mysub;
+#if defined(_DEBUG)
+	uint32_t tops;
+#endif
 
 	lwsl_info("%s: Enter\n", __func__);
 
@@ -1978,7 +1988,7 @@ lws_mqtt_client_send_unsubcribe(struct lws *wsi,
 
 			return 0;
 		}
-
+#if defined(_DEBUG)
 		/*
 		 * one or more of the topics needs to be unsubscribed
 		 * from, so we must go to the server with a filtered
@@ -1986,6 +1996,7 @@ lws_mqtt_client_send_unsubcribe(struct lws *wsi,
 		 */
 
 		tops = orphaned;
+#endif
 
 		if (lws_mqtt_fill_fixed_header(p++, LMQCP_CTOS_UNSUBSCRIBE,
 					       0, 0, 0)) {
diff --git a/lib/roles/raw-skt/ops-raw-skt.c b/lib/roles/raw-skt/ops-raw-skt.c
index 75d1776fb..9cdfe2f98 100644
--- a/lib/roles/raw-skt/ops-raw-skt.c
+++ b/lib/roles/raw-skt/ops-raw-skt.c
@@ -32,7 +32,7 @@ rops_handle_POLLIN_raw_skt(struct lws_context_per_thread *pt, struct lws *wsi,
 	const char *cce = NULL;
 #endif
 	struct lws_tokens ebuf;
-	int n, buffered;
+	int n = 0, buffered = 0;
 
 	/* pending truncated sends have uber priority */
 
diff --git a/lib/tls/openssl/openssl-client.c b/lib/tls/openssl/openssl-client.c
index cbf95f509..7d435806c 100644
--- a/lib/tls/openssl/openssl-client.c
+++ b/lib/tls/openssl/openssl-client.c
@@ -369,13 +369,17 @@ lws_tls_client_connect(struct lws *wsi)
 	char a[32];
 	unsigned int len;
 #endif
-	int m, n, en;
+	int m, n;
+#if defined(WIN32) || defined(_DEBUG)
+	int en;
+#endif
 
 	errno = 0;
 	ERR_clear_error();
 	n = SSL_connect(wsi->tls.ssl);
+#if defined(WIN32) || defined(_DEBUG)
 	en = errno;
-
+#endif
 	m = lws_ssl_get_error(wsi, n);
 
 	if (m == SSL_ERROR_SYSCALL
@@ -383,7 +387,9 @@ lws_tls_client_connect(struct lws *wsi)
 			&& en
 #endif
 	) {
+#if defined(WIN32) || defined(_DEBUG)
 		lwsl_info("%s: n %d, m %d, errno %d\n", __func__, n, m, en);
+#endif
 		return LWS_SSL_CAPABLE_ERROR;
 	}
 
diff --git a/minimal-examples/secure-streams/minimal-secure-streams-avs/avs.c b/minimal-examples/secure-streams/minimal-secure-streams-avs/avs.c
index 722b4a01f..fe8dd2eea 100644
--- a/minimal-examples/secure-streams/minimal-secure-streams-avs/avs.c
+++ b/minimal-examples/secure-streams/minimal-secure-streams-avs/avs.c
@@ -124,7 +124,11 @@ ss_avs_metadata_rx(void *userobj, const uint8_t *buf, size_t len, int flags)
 	lwsl_info("%s: len %d, buf h %d, t %d, space %d\n", __func__,
 		    (int)len, (int)m->head, (int)m->tail, (int)n);
 	lws_ss_get_est_peer_tx_credit(m->ss);
-	assert (len <= n);
+	if (len > n) {
+		assert(0);
+		lwsl_err("%s: bad len\n", __func__);
+		return 1;
+	}
 
 	if (m->head < m->tail)				/* |****h-------t**| */
 		memcpy(&m->buf[m->head], buf, len);