diff --git a/lib/context.c b/lib/context.c
index 37219cdb..9bed5901 100644
--- a/lib/context.c
+++ b/lib/context.c
@@ -256,6 +256,13 @@ lws_callback_http_dummy(struct lws *wsi, enum lws_callback_reasons reason,
 				wsi->reason_bf &= ~1;
 			break;
 		}
+
+		if (wsi->reason_bf & 4) {
+			n = lws_write(wsi, (unsigned char *)"0\x0d\x0a\x0d\x0a", 5, LWS_WRITE_HTTP);
+			if (n < 0)
+				return -1;
+			break;
+		}
 #endif
 #if defined(LWS_WITH_HTTP_PROXY)
 		if (wsi->reason_bf & 2) {
@@ -375,6 +382,11 @@ lws_callback_http_dummy(struct lws *wsi, enum lws_callback_reasons reason,
 		break;
 
 	case LWS_CALLBACK_CGI_TERMINATED:
+		if (!wsi->cgi->explicitly_chunked && !wsi->cgi->content_length) {
+			/* send terminating chunk */
+			wsi->reason_bf |= 4;
+			lws_callback_on_writable(wsi);
+		}
 		return -1;
 
 	case LWS_CALLBACK_CGI_STDIN_DATA:  /* POST body for stdin */
diff --git a/lib/libwebsockets.c b/lib/libwebsockets.c
index 3c0a0e74..57c7afc1 100755
--- a/lib/libwebsockets.c
+++ b/lib/libwebsockets.c
@@ -2793,6 +2793,11 @@ lws_cgi_write_split_stdout_headers(struct lws *wsi)
 					wsi->cgi->response_code);
 			if (lws_add_http_header_status(wsi, wsi->cgi->response_code, &p, end))
 				return 1;
+			if (!wsi->cgi->explicitly_chunked &&
+					!wsi->cgi->content_length &&
+					lws_add_http_header_by_token(wsi, WSI_TOKEN_HTTP_TRANSFER_ENCODING,
+					(unsigned char *)"chunked", 7, &p, end))
+				return 1;
 			if (lws_add_http_header_by_token(wsi, WSI_TOKEN_CONNECTION,
 					(unsigned char *)"close", 5, &p, end))
 				return 1;
@@ -2990,14 +2995,24 @@ lws_cgi_write_split_stdout_headers(struct lws *wsi)
 
 	/* payload processing */
 
+	m = !wsi->cgi->explicitly_chunked && !wsi->cgi->content_length;
+
 	n = read(lws_get_socket_fd(wsi->cgi->stdwsi[LWS_STDOUT]),
-		 start, sizeof(buf) - LWS_PRE);
+		 start, sizeof(buf) - LWS_PRE - (m ? LWS_HTTP_CHUNK_HDR_SIZE : 0));
 
 	if (n < 0 && errno != EAGAIN) {
 		lwsl_debug("%s: stdout read says %d\n", __func__, n);
 		return -1;
 	}
 	if (n > 0) {
+		if (m) {
+			char chdr[LWS_HTTP_CHUNK_HDR_SIZE];
+			m = lws_snprintf(chdr, LWS_HTTP_CHUNK_HDR_SIZE - 3, "%X\x0d\x0a", n);
+			memmove(start + m, start, n);
+			memcpy(start, chdr, m);
+			memcpy(start + m + n, "\x0d\x0a", 2);
+			n += m + 2;
+		}
 		m = lws_write(wsi, (unsigned char *)start, n, LWS_WRITE_HTTP);
 		//lwsl_notice("write %d\n", m);
 		if (m < 0) {
diff --git a/lib/private-libwebsockets.h b/lib/private-libwebsockets.h
index 1fd06b10..5b5b25df 100644
--- a/lib/private-libwebsockets.h
+++ b/lib/private-libwebsockets.h
@@ -1490,6 +1490,8 @@ struct _lws_websocket_related {
 
 #ifdef LWS_WITH_CGI
 
+#define LWS_HTTP_CHUNK_HDR_SIZE 16
+
 enum {
 	SIGNIFICANT_HDR_CONTENT_LENGTH,
 	SIGNIFICANT_HDR_LOCATION,