diff --git a/core/os/os.cpp b/core/os/os.cpp
index d81e70e6122a..7010d449301a 100644
--- a/core/os/os.cpp
+++ b/core/os/os.cpp
@@ -536,12 +536,21 @@ String OS::get_joy_guid(int p_device) const {
 
 void OS::set_context(int p_context) {
 }
+
+OS::SwitchVSyncCallbackInThread OS::switch_vsync_function = NULL;
+
 void OS::set_use_vsync(bool p_enable) {
+	_use_vsync = p_enable;
+	if (switch_vsync_function) { //if a function was set, use function
+		switch_vsync_function(p_enable);
+	} else { //otherwise just call here
+		_set_use_vsync(p_enable);
+	}
 }
 
 bool OS::is_vsync_enabled() const {
 
-	return true;
+	return _use_vsync;
 }
 
 OS::PowerState OS::get_power_state() {
diff --git a/core/os/os.h b/core/os/os.h
index d9f7b91daadc..2faaa6ab8f23 100644
--- a/core/os/os.h
+++ b/core/os/os.h
@@ -58,6 +58,7 @@ class OS {
 	int _exit_code;
 	int _orientation;
 	bool _allow_hidpi;
+	bool _use_vsync;
 
 	char *last_error;
 
@@ -435,8 +436,16 @@ class OS {
 
 	virtual void set_context(int p_context);
 
-	virtual void set_use_vsync(bool p_enable);
-	virtual bool is_vsync_enabled() const;
+	//amazing hack because OpenGL needs this to be set on a separate thread..
+	//also core can't access servers, so a callback must be used
+	typedef void (*SwitchVSyncCallbackInThread)(bool);
+
+	static SwitchVSyncCallbackInThread switch_vsync_function;
+	void set_use_vsync(bool p_enable);
+	bool is_vsync_enabled() const;
+
+	//real, actual overridable function to switch vsync, which needs to be called from graphics thread if needed
+	virtual void _set_use_vsync(bool p_enable) {}
 
 	virtual OS::PowerState get_power_state();
 	virtual int get_power_seconds_left();
diff --git a/platform/osx/os_osx.h b/platform/osx/os_osx.h
index ede50a05babb..2381b856580c 100644
--- a/platform/osx/os_osx.h
+++ b/platform/osx/os_osx.h
@@ -215,8 +215,8 @@ class OS_OSX : public OS_Unix {
 
 	virtual bool _check_internal_feature_support(const String &p_feature);
 
-	virtual void set_use_vsync(bool p_enable);
-	virtual bool is_vsync_enabled() const;
+	virtual void _set_use_vsync(bool p_enable);
+	//virtual bool is_vsync_enabled() const;
 
 	void run();
 
diff --git a/platform/osx/os_osx.mm b/platform/osx/os_osx.mm
index f3809e6eedd4..aab37cb59c23 100644
--- a/platform/osx/os_osx.mm
+++ b/platform/osx/os_osx.mm
@@ -2063,14 +2063,14 @@ static int get_screen_index(NSScreen *screen) {
 	return OK;
 }
 
-void OS_OSX::set_use_vsync(bool p_enable) {
+void OS_OSX::_set_use_vsync(bool p_enable) {
 	CGLContextObj ctx = CGLGetCurrentContext();
 	if (ctx) {
 		GLint swapInterval = p_enable ? 1 : 0;
 		CGLSetParameter(ctx, kCGLCPSwapInterval, &swapInterval);
 	}
 }
-
+/*
 bool OS_OSX::is_vsync_enabled() const {
 	GLint swapInterval = 0;
 	CGLContextObj ctx = CGLGetCurrentContext();
@@ -2079,7 +2079,7 @@ static int get_screen_index(NSScreen *screen) {
 	}
 	return swapInterval ? true : false;
 }
-
+*/
 OS_OSX *OS_OSX::singleton = NULL;
 
 OS_OSX::OS_OSX() {
diff --git a/platform/windows/os_windows.cpp b/platform/windows/os_windows.cpp
index 6cab683e837a..d3fa2bbc0de0 100644
--- a/platform/windows/os_windows.cpp
+++ b/platform/windows/os_windows.cpp
@@ -2288,19 +2288,19 @@ String OS_Windows::get_joy_guid(int p_device) const {
 	return input->get_joy_guid_remapped(p_device);
 }
 
-void OS_Windows::set_use_vsync(bool p_enable) {
+void OS_Windows::_set_use_vsync(bool p_enable) {
 
 	if (gl_context)
 		gl_context->set_use_vsync(p_enable);
 }
-
+/*
 bool OS_Windows::is_vsync_enabled() const {
 
 	if (gl_context)
 		return gl_context->is_using_vsync();
 
 	return true;
-}
+}*/
 
 OS::PowerState OS_Windows::get_power_state() {
 	return power_manager->get_power_state();
diff --git a/platform/windows/os_windows.h b/platform/windows/os_windows.h
index f2226a53a99d..7c5490a0a407 100644
--- a/platform/windows/os_windows.h
+++ b/platform/windows/os_windows.h
@@ -275,8 +275,8 @@ class OS_Windows : public OS {
 	virtual bool is_joy_known(int p_device);
 	virtual String get_joy_guid(int p_device) const;
 
-	virtual void set_use_vsync(bool p_enable);
-	virtual bool is_vsync_enabled() const;
+	virtual void _set_use_vsync(bool p_enable);
+	//virtual bool is_vsync_enabled() const;
 
 	virtual OS::PowerState get_power_state();
 	virtual int get_power_seconds_left();
diff --git a/platform/x11/os_x11.cpp b/platform/x11/os_x11.cpp
index 0c0bc1a8a3f9..6616e4731767 100644
--- a/platform/x11/os_x11.cpp
+++ b/platform/x11/os_x11.cpp
@@ -2306,11 +2306,11 @@ String OS_X11::get_joy_guid(int p_device) const {
 	return input->get_joy_guid_remapped(p_device);
 }
 
-void OS_X11::set_use_vsync(bool p_enable) {
+void OS_X11::_set_use_vsync(bool p_enable) {
 	if (context_gl)
 		return context_gl->set_use_vsync(p_enable);
 }
-
+/*
 bool OS_X11::is_vsync_enabled() const {
 
 	if (context_gl)
@@ -2318,7 +2318,7 @@ bool OS_X11::is_vsync_enabled() const {
 
 	return true;
 }
-
+*/
 void OS_X11::set_context(int p_context) {
 
 	XClassHint *classHint = XAllocClassHint();
diff --git a/platform/x11/os_x11.h b/platform/x11/os_x11.h
index c8cea1e30cae..86f25918fd0d 100644
--- a/platform/x11/os_x11.h
+++ b/platform/x11/os_x11.h
@@ -270,8 +270,8 @@ class OS_X11 : public OS_Unix {
 
 	virtual void set_context(int p_context);
 
-	virtual void set_use_vsync(bool p_enable);
-	virtual bool is_vsync_enabled() const;
+	virtual void _set_use_vsync(bool p_enable);
+	//virtual bool is_vsync_enabled() const;
 
 	virtual OS::PowerState get_power_state();
 	virtual int get_power_seconds_left();
diff --git a/servers/visual/visual_server_raster.cpp b/servers/visual/visual_server_raster.cpp
index 6b527b5cd102..7bb7d04fcd6c 100644
--- a/servers/visual/visual_server_raster.cpp
+++ b/servers/visual/visual_server_raster.cpp
@@ -181,6 +181,10 @@ void VisualServerRaster::set_debug_generate_wireframes(bool p_generate) {
 	VSG::storage->set_debug_generate_wireframes(p_generate);
 }
 
+void VisualServerRaster::call_set_use_vsync(bool p_enable) {
+	OS::get_singleton()->_set_use_vsync(p_enable);
+}
+
 VisualServerRaster::VisualServerRaster() {
 
 	VSG::canvas = memnew(VisualServerCanvas);
diff --git a/servers/visual/visual_server_raster.h b/servers/visual/visual_server_raster.h
index a0e79e9d3e5d..716c1754e1ec 100644
--- a/servers/visual/visual_server_raster.h
+++ b/servers/visual/visual_server_raster.h
@@ -668,6 +668,8 @@ class VisualServerRaster : public VisualServer {
 	virtual bool has_os_feature(const String &p_feature) const;
 	virtual void set_debug_generate_wireframes(bool p_generate);
 
+	virtual void call_set_use_vsync(bool p_enable);
+
 	VisualServerRaster();
 	~VisualServerRaster();
 
diff --git a/servers/visual/visual_server_wrap_mt.cpp b/servers/visual/visual_server_wrap_mt.cpp
index b86a0ae3f625..e55b7a93095c 100644
--- a/servers/visual/visual_server_wrap_mt.cpp
+++ b/servers/visual/visual_server_wrap_mt.cpp
@@ -158,9 +158,19 @@ void VisualServerWrapMT::finish() {
 	canvas_occluder_polygon_free_cached_ids();
 }
 
+void VisualServerWrapMT::set_use_vsync_callback(bool p_enable) {
+
+	singleton_mt->call_set_use_vsync(p_enable);
+}
+
+VisualServerWrapMT *VisualServerWrapMT::singleton_mt = NULL;
+
 VisualServerWrapMT::VisualServerWrapMT(VisualServer *p_contained, bool p_create_thread) :
 		command_queue(p_create_thread) {
 
+	singleton_mt = this;
+	OS::switch_vsync_function = set_use_vsync_callback; //as this goes to another thread, make sure it goes properly
+
 	visual_server = p_contained;
 	create_thread = p_create_thread;
 	thread = NULL;
diff --git a/servers/visual/visual_server_wrap_mt.h b/servers/visual/visual_server_wrap_mt.h
index cb6f67474ed5..0f24521f5dad 100644
--- a/servers/visual/visual_server_wrap_mt.h
+++ b/servers/visual/visual_server_wrap_mt.h
@@ -64,6 +64,8 @@ class VisualServerWrapMT : public VisualServer {
 
 	//#define DEBUG_SYNC
 
+	static VisualServerWrapMT *singleton_mt;
+
 #ifdef DEBUG_SYNC
 #define SYNC_DEBUG print_line("sync on: " + String(__FUNCTION__));
 #else
@@ -584,6 +586,10 @@ class VisualServerWrapMT : public VisualServer {
 	virtual bool has_feature(Features p_feature) const { return visual_server->has_feature(p_feature); }
 	virtual bool has_os_feature(const String &p_feature) const { return visual_server->has_os_feature(p_feature); }
 
+	FUNC1(call_set_use_vsync, bool)
+
+	static void set_use_vsync_callback(bool p_enable);
+
 	VisualServerWrapMT(VisualServer *p_contained, bool p_create_thread);
 	~VisualServerWrapMT();
 
diff --git a/servers/visual_server.cpp b/servers/visual_server.cpp
index c0b53c2d9aca..42ecb82a4600 100644
--- a/servers/visual_server.cpp
+++ b/servers/visual_server.cpp
@@ -1922,6 +1922,7 @@ VisualServer::VisualServer() {
 
 	//ERR_FAIL_COND(singleton);
 	singleton = this;
+
 	GLOBAL_DEF("rendering/vram_compression/import_s3tc", true);
 	GLOBAL_DEF("rendering/vram_compression/import_etc", false);
 	GLOBAL_DEF("rendering/vram_compression/import_etc2", true);
diff --git a/servers/visual_server.h b/servers/visual_server.h
index ff1f3cf0b970..23354c3d3734 100644
--- a/servers/visual_server.h
+++ b/servers/visual_server.h
@@ -980,6 +980,8 @@ class VisualServer : public Object {
 
 	virtual void set_debug_generate_wireframes(bool p_generate) = 0;
 
+	virtual void call_set_use_vsync(bool p_enable) = 0;
+
 	VisualServer();
 	virtual ~VisualServer();
 };