diff --git a/src/bindings/csharp/openalpr-net/bitmapmat-net.h b/src/bindings/csharp/openalpr-net/bitmapmat-net.h
index a65acf3..cedbf94 100644
--- a/src/bindings/csharp/openalpr-net/bitmapmat-net.h
+++ b/src/bindings/csharp/openalpr-net/bitmapmat-net.h
@@ -65,7 +65,7 @@ namespace openalprnet {
 				channels = 4;
 				break;
 			default:
-				throw gcnew NotImplementedException();
+				throw gcnew NotSupportedException(bitmap->PixelFormat.ToString());
 			}
 
 			BitmapData^ bitmapData = bitmap->LockBits(