diff --git a/SourceS/ui_fwd.h b/SourceS/ui_fwd.h
index 4bea142ed..2613b510b 100644
--- a/SourceS/ui_fwd.h
+++ b/SourceS/ui_fwd.h
@@ -2,10 +2,10 @@
 
 namespace dvl {
 
-extern int screenWidth;
-extern int screenHeight;
-extern int viewportHeight;
-extern int borderRight;
+extern Sint16 screenWidth;
+extern Sint16 screenHeight;
+extern Sint16 viewportHeight;
+extern Sint16 borderRight;
 
 bool SpawnWindow(const char *lpWindowName);
 void UiErrorOkDialog(const char *text, const char *caption, bool error = true);
diff --git a/SourceX/display.cpp b/SourceX/display.cpp
index 9c97c58f8..366482581 100644
--- a/SourceX/display.cpp
+++ b/SourceX/display.cpp
@@ -22,10 +22,10 @@ namespace dvl {
 
 extern SDL_Surface *renderer_texture_surface; /** defined in dx.cpp */
 
-int screenWidth;
-int screenHeight;
-int viewportHeight;
-int borderRight;
+Sint16 screenWidth;
+Sint16 screenHeight;
+Sint16 viewportHeight;
+Sint16 borderRight;
 
 #ifdef USE_SDL1
 void SetVideoMode(int width, int height, int bpp, uint32_t flags)
diff --git a/SourceX/display.h b/SourceX/display.h
index 298563941..243c03e92 100644
--- a/SourceX/display.h
+++ b/SourceX/display.h
@@ -8,7 +8,7 @@
 
 namespace dvl {
 
-extern int vsyncEnabled;
+extern bool vsyncEnabled;
 extern int refreshDelay; // Screen refresh rate in nanoseconds
 extern SDL_Window *window;
 extern SDL_Renderer *renderer;
diff --git a/SourceX/dx.cpp b/SourceX/dx.cpp
index bbd63e79a..49db731ca 100644
--- a/SourceX/dx.cpp
+++ b/SourceX/dx.cpp
@@ -21,7 +21,6 @@ int locktbl[256];
 #endif
 static CCritSect sgMemCrit;
 
-int vsyncEnabled;
 int refreshDelay;
 SDL_Renderer *renderer;
 SDL_Texture *texture;
@@ -290,7 +289,7 @@ void RenderPresent()
 		}
 		SDL_RenderPresent(renderer);
 
-		if (!vsyncEnabled) {
+		if (!sgOptions.bVSync) {
 			LimitFrameRate();
 		}
 	} else {