diff --git a/stepmania/src/RageDisplay.cpp b/stepmania/src/RageDisplay.cpp
index 0b1e991980..8ae1779718 100644
--- a/stepmania/src/RageDisplay.cpp
+++ b/stepmania/src/RageDisplay.cpp
@@ -635,9 +635,14 @@ bool RageDisplay::SaveScreenshot( CString sPath, GraphicsFileFormat format )
 	if( format != SAVE_LOSSLESS )
 	{
 		/* Maintain the DAR. */
-		int iWidth = lrintf( 640 / GetActualVideoModeParams().fDisplayAspectRatio );
-		LOG->Trace( "%ix%i -> %ix%i (%.3f)", surface->w, surface->h, 640, iWidth, GetActualVideoModeParams().fDisplayAspectRatio );
-		RageSurfaceUtils::Zoom( surface, 640, iWidth );
+		float fDAR = GetActualVideoModeParams().fDisplayAspectRatio;
+		
+		// -1 seems to be a sentinel
+		if( fDAR < 0.0f )
+			fDAR = 4.0f/3.0f;
+		int iHeight = lrintf( 640 / fDAR );
+		LOG->Trace( "%ix%i -> %ix%i (%.3f)", surface->w, surface->h, 640, iHeight, fDAR );
+		RageSurfaceUtils::Zoom( surface, 640, iHeight );
 	}
 
 	RageFile out;