diff --git a/clang/utils/TableGen/ClangOpenCLBuiltinEmitter.cpp b/clang/utils/TableGen/ClangOpenCLBuiltinEmitter.cpp
index 25c7bf0306a891..2a369271cfc3f2 100644
--- a/clang/utils/TableGen/ClangOpenCLBuiltinEmitter.cpp
+++ b/clang/utils/TableGen/ClangOpenCLBuiltinEmitter.cpp
@@ -22,6 +22,7 @@
 #include "llvm/ADT/StringExtras.h"
 #include "llvm/ADT/StringMap.h"
 #include "llvm/ADT/StringRef.h"
+#include "llvm/ADT/StringSet.h"
 #include "llvm/ADT/StringSwitch.h"
 #include "llvm/Support/ErrorHandling.h"
 #include "llvm/Support/raw_ostream.h"
@@ -889,14 +890,14 @@ static void OCL2Qual(Sema &S, const OpenCLTypeStruct &Ty,
   // Only insert the plain scalar type; vector information and type qualifiers
   // are added in step 2.
   ArrayRef<const Record *> Types = Records.getAllDerivedDefinitions("Type");
-  StringMap<bool> TypesSeen;
+  StringSet<> TypesSeen;
 
   for (const auto *T : Types) {
     // Check this is not an image type
     if (ImageTypesMap.contains(T->getValueAsString("Name")))
       continue;
     // Check we have not seen this Type
-    if (!TypesSeen.try_emplace(T->getValueAsString("Name"), true).second)
+    if (!TypesSeen.insert(T->getValueAsString("Name")).second)
       continue;
 
     // Check the Type does not have an "abstract" QualType