diff --git a/clang/lib/Sema/Sema.cpp b/clang/lib/Sema/Sema.cpp
index 22929aa6316d7..cafbecebc8a11 100644
--- a/clang/lib/Sema/Sema.cpp
+++ b/clang/lib/Sema/Sema.cpp
@@ -870,6 +870,7 @@ static void checkUndefinedButUsed(Sema &S) {
   // Collect all the still-undefined entities with internal linkage.
   SmallVector<std::pair<NamedDecl *, SourceLocation>, 16> Undefined;
   S.getUndefinedButUsed(Undefined);
+  S.UndefinedButUsed.clear();
   if (Undefined.empty()) return;
 
   for (const auto &Undef : Undefined) {
@@ -923,8 +924,6 @@ static void checkUndefinedButUsed(Sema &S) {
     if (UseLoc.isValid())
       S.Diag(UseLoc, diag::note_used_here);
   }
-
-  S.UndefinedButUsed.clear();
 }
 
 void Sema::LoadExternalWeakUndeclaredIdentifiers() {