diff --git a/lib/Sema/SemaOverload.cpp b/lib/Sema/SemaOverload.cpp
index 42eced4..acaa3ba 100644
--- a/lib/Sema/SemaOverload.cpp
+++ b/lib/Sema/SemaOverload.cpp
@@ -6219,6 +6219,8 @@
   }
 }
 
+namespace {
+
 /// BuiltinCandidateTypeSet - A set of types that will be used for the
 /// candidate operator functions for built-in operators (C++
 /// [over.built]). The types are separated into pointer types and
@@ -6308,6 +6310,8 @@
   bool hasNullPtrType() const { return HasNullPtrType; }
 };
 
+} // end anonymous namespace
+
 /// AddPointerWithMoreQualifiedTypeVariants - Add the pointer type @p Ty to
 /// the set of pointer types along with any more-qualified variants of
 /// that type. For example, if @p Ty is "int const *", this routine