diff --git a/sc2/src/sc2code/libs/graphics/sdl/3do_blt.c b/sc2/src/sc2code/libs/graphics/sdl/3do_blt.c
index 4247dfabe..298e7c2ec 100644
--- a/sc2/src/sc2code/libs/graphics/sdl/3do_blt.c
+++ b/sc2/src/sc2code/libs/graphics/sdl/3do_blt.c
@@ -45,14 +45,14 @@ blt (PRECT pClipRect, PRIMITIVEPTR PrimPtr)
 
 	img = (TFB_Image *) ((BYTE *) SrcFramePtr + SrcFramePtr->DataOffs);
 	
-	LockMutex (img->mutex);
-
 	if (TYPE_GET (_CurFramePtr->TypeIndexAndFlags) == SCREEN_DRAWABLE)
 	{
 		int x, y;
 		BOOLEAN scaled, paletted, filled;
 		TFB_Palette palette[256];
 
+		LockMutex (img->mutex);
+
 		x = pClipRect->corner.x - GetFrameHotX (_CurFramePtr);
 		y = pClipRect->corner.y - GetFrameHotY (_CurFramePtr);
 		scaled = filled = FALSE;