diff --git a/.vscode/settings.json b/.vscode/settings.json
new file mode 100644
index 0000000000..0db587396d
--- /dev/null
+++ b/.vscode/settings.json
@@ -0,0 +1,3 @@
+{
+    "cmake.configureOnOpen": true
+}
\ No newline at end of file
diff --git a/include/libwebsockets.h b/include/libwebsockets.h
index 87ff280885..bd8ad36c56 100644
--- a/include/libwebsockets.h
+++ b/include/libwebsockets.h
@@ -702,6 +702,7 @@ lws_fx_string(const lws_fx_t *a, char *buf, size_t size);
 #if defined(LWS_ROLE_MQTT)
 #include <libwebsockets/lws-mqtt.h>
 #endif
+#include <libwebsockets/lws-assert.h>
 #include <libwebsockets/lws-client.h>
 #include <libwebsockets/lws-http.h>
 #include <libwebsockets/lws-spa.h>
diff --git a/include/libwebsockets/lws-assert.h b/include/libwebsockets/lws-assert.h
new file mode 100644
index 0000000000..2a2d986da1
--- /dev/null
+++ b/include/libwebsockets/lws-assert.h
@@ -0,0 +1,21 @@
+#if !defined(__LWS_ASSERT_H__)
+#define __LWS_ASSERT_H__
+
+
+
+
+typedef void (*lws_assert_cb)(const char *file, int line, const char *expression);
+void lws_set_assert_cb(lws_assert_cb cb);
+
+#ifdef  LWS_ENABLE_CUSTOM_ASSERT
+void lws_assert(const char *file, int line, const char *expression);
+#   ifdef assert
+#       undef assert
+#   endif
+#define assert(expression) (void)((expression) || (lws_assert(__FILE__, __LINE__, #expression), 0))
+#endif
+
+
+
+
+#endif
\ No newline at end of file
diff --git a/lib/core/CMakeLists.txt b/lib/core/CMakeLists.txt
index bd0b05d6f9..93270fb05b 100644
--- a/lib/core/CMakeLists.txt
+++ b/lib/core/CMakeLists.txt
@@ -32,6 +32,7 @@ if (NOT LWS_ONLY_SSPC)
 
 	list(APPEND SOURCES
 		core/alloc.c
+		core/assert.c
 		core/buflist.c
 		core/context.c
 		core/lws_map.c
diff --git a/lib/core/assert.c b/lib/core/assert.c
new file mode 100644
index 0000000000..cdf3330756
--- /dev/null
+++ b/lib/core/assert.c
@@ -0,0 +1,16 @@
+#include "private-lib-core.h"
+
+static lws_assert_cb assert_cb = NULL;
+
+void lws_set_assert_cb(lws_assert_cb cb) {
+    assert_cb = cb;
+}
+
+void lws_assert(const char *file, int line, const char *expression) {
+    if (assert_cb != NULL) {
+        assert_cb(file, line, expression);
+    } else {
+        fprintf(stderr, "Assertion failed: %s, file %s, line %d\n", expression, file, line);
+        abort();
+    }
+}
diff --git a/lib/core/private-lib-core.h b/lib/core/private-lib-core.h
index f894f2debc..595571fbf8 100644
--- a/lib/core/private-lib-core.h
+++ b/lib/core/private-lib-core.h
@@ -147,6 +147,7 @@
   *
   */
 
+#define LWS_ENABLE_CUSTOM_ASSERT
 #include "libwebsockets.h"
 
 /*
diff --git a/lib/roles/http/client/client-http.c b/lib/roles/http/client/client-http.c
index 70373bbcd9..3f9c7784d8 100644
--- a/lib/roles/http/client/client-http.c
+++ b/lib/roles/http/client/client-http.c
@@ -286,7 +286,7 @@ lws_http_client_socket_service(struct lws *wsi, struct lws_pollfd *pollfd)
 			lwsl_debug("ERROR writing to client socket\n");
 			lws_close_free_wsi(wsi, LWS_CLOSE_STATUS_NOSTATUS,
 					   "cws");
-			return 0;
+			return -1;	// closed wsi so let callers know
 		case LWS_SSL_CAPABLE_MORE_SERVICE:
 			lws_callback_on_writable(wsi);
 			break;
diff --git a/make.sh b/make.sh
new file mode 100755
index 0000000000..d731fa603a
--- /dev/null
+++ b/make.sh
@@ -0,0 +1,5 @@
+rm -rf build
+mkdir build
+cd build
+cmake .. -DLWS_WITH_MINIMAL_EXAMPLES=1
+make