diff --git a/src/pystencils_autodiff/backends/astnodes.py b/src/pystencils_autodiff/backends/astnodes.py
index ccab812be7d2186a7cd840f7b0cb96ad80e12e6a..6b8f12d4b1057e3effc28c825b28017358dede44 100644
--- a/src/pystencils_autodiff/backends/astnodes.py
+++ b/src/pystencils_autodiff/backends/astnodes.py
@@ -144,7 +144,7 @@ setup_pybind11(cfg)
 
         assert not self.is_cuda
 
-        source_code = str(self)
+        source_code = self.CPP_IMPORT_PREFIX + str(self)
         file_name = join(pystencils.cache.cache_dir, f'{self.module_name}.cpp')
 
         if not exists(file_name):