diff --git a/src/v_video.cpp b/src/v_video.cpp
index aca00cfb37..d993204a27 100644
--- a/src/v_video.cpp
+++ b/src/v_video.cpp
@@ -72,6 +72,7 @@ FRenderer *Renderer;
 
 IMPLEMENT_CLASS(DCanvas, true, false)
 IMPLEMENT_CLASS(DFrameBuffer, true, false)
+EXTERN_CVAR (Bool, fullscreen)
 
 #if defined(_DEBUG) && defined(_M_IX86) && !defined(__MINGW32__)
 #define DBGBREAK	{ __asm int 3 }
@@ -1489,6 +1490,9 @@ CCMD (vid_setmode)
 		goodmode = true;
 	}
 
+	if (!fullscreen)
+		goodmode = true;
+
 	if (goodmode)
 	{
 		// The actual change of resolution will take place