diff --git a/OpenRa.Gl/GraphicsDevice.cs b/OpenRa.Gl/GraphicsDevice.cs
index 0ded13ddae..76ce6581a3 100644
--- a/OpenRa.Gl/GraphicsDevice.cs
+++ b/OpenRa.Gl/GraphicsDevice.cs
@@ -60,10 +60,17 @@ namespace OpenRa.GlRenderer
 			Sdl.SDL_GL_SetAttribute(Sdl.SDL_GL_ALPHA_SIZE, 8);
 
 
-			// Breaks os x usability
-			//Environment.SetEnvironmentVariable("SDL_VIDEO_WINDOW_POS", "0,0");
-			//surf = Sdl.SDL_SetVideoMode(width, height, 0, Sdl.SDL_NOFRAME | Sdl.SDL_OPENGL | (windowed ? 0 : Sdl.SDL_FULLSCREEN));
-			surf = Sdl.SDL_SetVideoMode(width, height, 0, Sdl.SDL_OPENGL | (windowed ? 0 : Sdl.SDL_FULLSCREEN));
+			if (Environment.OSVersion.Platform == PlatformID.Win32NT)
+			{
+				// pseudo-fullscreen, for sane debugging.
+				Environment.SetEnvironmentVariable("SDL_VIDEO_WINDOW_POS", "0,0");
+				surf = Sdl.SDL_SetVideoMode(width, height, 0, Sdl.SDL_NOFRAME | Sdl.SDL_OPENGL | (windowed ? 0 : Sdl.SDL_FULLSCREEN));
+			}
+			else
+			{
+				// OSX doesn't like this, due to quirks of their WM.
+				surf = Sdl.SDL_SetVideoMode(width, height, 0, Sdl.SDL_OPENGL | (windowed ? 0 : Sdl.SDL_FULLSCREEN));
+			}
 
 			Sdl.SDL_WM_SetCaption("OpenRA", "OpenRA");
 			Sdl.SDL_ShowCursor(0);