diff --git a/ProcessLib/SourceTerms/Python/PythonSourceTermLocalAssembler.h b/ProcessLib/SourceTerms/Python/PythonSourceTermLocalAssembler.h
index 99b41376e121c4a8b735d12cde4e90a9b097ed01..a9078ccc970dca944df52f1c5db9def61937d569 100644
--- a/ProcessLib/SourceTerms/Python/PythonSourceTermLocalAssembler.h
+++ b/ProcessLib/SourceTerms/Python/PythonSourceTermLocalAssembler.h
@@ -218,7 +218,7 @@ public:
 private:
     PythonSourceTermData const& _data;
     MeshLib::Element const& _element;
-    bool _is_axially_symmetric;
+    bool const _is_axially_symmetric;
 
     IntegrationMethod const _integration_method;
     std::vector<