diff --git a/clang-tools-extra/clang-change-namespace/ChangeNamespace.cpp b/clang-tools-extra/clang-change-namespace/ChangeNamespace.cpp
index 879c0d26d472..850df7daf5c0 100644
--- a/clang-tools-extra/clang-change-namespace/ChangeNamespace.cpp
+++ b/clang-tools-extra/clang-change-namespace/ChangeNamespace.cpp
@@ -606,9 +606,8 @@ void ChangeNamespaceTool::run(
                  Result.Nodes.getNodeAs<DeclRefExpr>("func_ref")) {
     // If this reference has been processed as a function call, we do not
     // process it again.
-    if (ProcessedFuncRefs.count(FuncRef))
+    if (!ProcessedFuncRefs.insert(FuncRef).second)
       return;
-    ProcessedFuncRefs.insert(FuncRef);
     const auto *Func = Result.Nodes.getNodeAs<FunctionDecl>("func_decl");
     assert(Func);
     const auto *Context = Result.Nodes.getNodeAs<Decl>("dc");