diff --git a/Source/cmFileSet.cxx b/Source/cmFileSet.cxx
index 066a49428c..6e10489536 100644
--- a/Source/cmFileSet.cxx
+++ b/Source/cmFileSet.cxx
@@ -156,7 +156,7 @@ cmFileSet::CompileDirectoryEntries() const
 
 std::vector<std::string> cmFileSet::EvaluateDirectoryEntries(
   std::vector<std::unique_ptr<cmCompiledGeneratorExpression>> const& cges,
-  cmLocalGenerator* lg, std::string const& config,
+  cmLocalGenerator const* lg, std::string const& config,
   cmGeneratorTarget const* target,
   cmGeneratorExpressionDAGChecker* dagChecker) const
 {
@@ -218,7 +218,7 @@ void cmFileSet::EvaluateFileEntry(
   std::vector<std::string> const& dirs,
   std::map<std::string, std::vector<std::string>>& filesPerDir,
   std::unique_ptr<cmCompiledGeneratorExpression> const& cge,
-  cmLocalGenerator* lg, std::string const& config,
+  cmLocalGenerator const* lg, std::string const& config,
   cmGeneratorTarget const* target,
   cmGeneratorExpressionDAGChecker* dagChecker) const
 {
diff --git a/Source/cmFileSet.h b/Source/cmFileSet.h
index 1175be81ff..ac2fb78361 100644
--- a/Source/cmFileSet.h
+++ b/Source/cmFileSet.h
@@ -67,7 +67,7 @@ public:
 
   std::vector<std::string> EvaluateDirectoryEntries(
     std::vector<std::unique_ptr<cmCompiledGeneratorExpression>> const& cges,
-    cmLocalGenerator* lg, std::string const& config,
+    cmLocalGenerator const* lg, std::string const& config,
     cmGeneratorTarget const* target,
     cmGeneratorExpressionDAGChecker* dagChecker = nullptr) const;
 
@@ -75,7 +75,7 @@ public:
     std::vector<std::string> const& dirs,
     std::map<std::string, std::vector<std::string>>& filesPerDir,
     std::unique_ptr<cmCompiledGeneratorExpression> const& cge,
-    cmLocalGenerator* lg, std::string const& config,
+    cmLocalGenerator const* lg, std::string const& config,
     cmGeneratorTarget const* target,
     cmGeneratorExpressionDAGChecker* dagChecker = nullptr) const;