diff --git a/python/pystencils_walberla/cmake_integration.py b/python/pystencils_walberla/cmake_integration.py
index 6b0ce87e3043643d23955bdbd2a29a891d3fad6c..6c842838b536b8f547d55280cfd826d0fe51ce7a 100644
--- a/python/pystencils_walberla/cmake_integration.py
+++ b/python/pystencils_walberla/cmake_integration.py
@@ -38,7 +38,8 @@ class CodeGeneration:
                     [os.path.basename(p) for p in only_in_cmake])
             if only_generated:
                 error_message += "Unexpected generated files {}\n".format([os.path.basename(p) for p in only_generated])
-            raise ValueError(error_message)
+            if len(only_in_cmake) > 0 or len(only_generated) > 0:
+                raise ValueError(error_message)
 
 
 def parse_json_args():