diff --git a/lldb/source/Plugins/ExpressionParser/Clang/ClangPersistentVariables.h b/lldb/source/Plugins/ExpressionParser/Clang/ClangPersistentVariables.h
index f6298911dd6c..f888b2d56e68 100644
--- a/lldb/source/Plugins/ExpressionParser/Clang/ClangPersistentVariables.h
+++ b/lldb/source/Plugins/ExpressionParser/Clang/ClangPersistentVariables.h
@@ -51,7 +51,7 @@ public:
 
   void RemovePersistentVariable(lldb::ExpressionVariableSP variable) override;
 
-  virtual ConstString GetNextPersistentVariableName(bool is_error = false);
+  ConstString GetNextPersistentVariableName(bool is_error = false) override;
 
   /// Returns the next file name that should be used for user expressions.
   std::string GetNextExprFileName() {