diff --git a/project/include/system/System.h b/project/include/system/System.h
index 23cfb7bb9..ec67cdd16 100644
--- a/project/include/system/System.h
+++ b/project/include/system/System.h
@@ -28,6 +28,8 @@ namespace lime {
 
 			static void GCEnterBlocking ();
 			static void GCExitBlocking ();
+			static void GCTryEnterBlocking ();
+			static void GCTryExitBlocking ();
 			static bool GetAllowScreenTimeout ();
 			static std::wstring* GetDeviceModel ();
 			static std::wstring* GetDeviceVendor ();
diff --git a/project/src/backend/sdl/SDLApplication.cpp b/project/src/backend/sdl/SDLApplication.cpp
index 190b7e52b..85e64fa1b 100644
--- a/project/src/backend/sdl/SDLApplication.cpp
+++ b/project/src/backend/sdl/SDLApplication.cpp
@@ -928,8 +928,16 @@ namespace lime {
 
 	void SDLApplication::UpdateFrame () {
 
+		#ifdef EMSCRIPTEN
+		System::GCTryExitBlocking ();
+		#endif
+
 		currentApplication->Update ();
 
+		#ifdef EMSCRIPTEN
+		System::GCTryEnterBlocking ();
+		#endif
+
 	}
 
 
diff --git a/project/src/backend/sdl/SDLWindow.cpp b/project/src/backend/sdl/SDLWindow.cpp
index 59ff7435f..e58103f3e 100644
--- a/project/src/backend/sdl/SDLWindow.cpp
+++ b/project/src/backend/sdl/SDLWindow.cpp
@@ -201,7 +201,9 @@ namespace lime {
 
 			// if (window->flags & WINDOW_FLAG_VSYNC) {
 
-			// 	sdlRendererFlags |= SDL_RENDERER_PRESENTVSYNC;
+			#ifdef EMSCRIPTEN
+			sdlRendererFlags |= SDL_RENDERER_PRESENTVSYNC;
+			#endif
 
 			// }
 
diff --git a/project/src/system/System.cpp b/project/src/system/System.cpp
index 820a3d4a6..4385ae268 100644
--- a/project/src/system/System.cpp
+++ b/project/src/system/System.cpp
@@ -42,6 +42,28 @@ namespace lime {
 	}
 
 
+	void System::GCTryEnterBlocking () {
+
+		if (!_isHL) {
+
+			gc_try_blocking ();
+
+		}
+
+	}
+
+
+	void System::GCTryExitBlocking () {
+
+		if (!_isHL) {
+
+			gc_try_unblocking ();
+
+		}
+
+	}
+
+
 	#if defined (HX_WINDOWS) && !defined (HX_WINRT)
 	std::wstring* GetWMIValue (BSTR query, BSTR field) {
 
diff --git a/tools/platforms/WebAssemblyPlatform.hx b/tools/platforms/WebAssemblyPlatform.hx
index d79827769..b7e48b255 100644
--- a/tools/platforms/WebAssemblyPlatform.hx
+++ b/tools/platforms/WebAssemblyPlatform.hx
@@ -206,6 +206,10 @@ class WebAssemblyPlatform extends PlatformTarget
 			args.push("ASSERTIONS=1");
 		}
 
+		// set initial size
+		args.push("-s");
+		args.push("TOTAL_MEMORY=32MB");
+
 		if (project.targetFlags.exists("final"))
 		{
 			args.push("-O3");