diff --git a/Source/Core/Data/TextureImage.cs b/Source/Core/Data/TextureImage.cs
index 8127f50a198f5f04e36d7f132c499fd0485df2fb..5abd35e14fdcb5433a339e2fe736c8181e7a7ab1 100755
--- a/Source/Core/Data/TextureImage.cs
+++ b/Source/Core/Data/TextureImage.cs
@@ -110,7 +110,7 @@ namespace CodeImp.DoomBuilder.Data
 					{
 						// Get a reader for the data
 						Bitmap patchbmp = ImageDataFormat.TryLoadImage(patchdata, ImageDataFormat.DOOMPICTURE, General.Map.Data.Palette);
-						if(patchbmp != null)
+						if(patchbmp == null)
 						{
 							//mxd. Probably that's a flat?..
 							if(General.Map.Config.MixTexturesFlats)