diff --git a/clang/lib/Sema/SemaExprCXX.cpp b/clang/lib/Sema/SemaExprCXX.cpp
index 46844d7662d0..48b49f550cf3 100644
--- a/clang/lib/Sema/SemaExprCXX.cpp
+++ b/clang/lib/Sema/SemaExprCXX.cpp
@@ -3938,16 +3938,10 @@ ExprResult Sema::BuildBinaryTypeTrait(BinaryTypeTrait BTT,
   if (!LhsT->isDependentType() && !RhsT->isDependentType())
     Value = EvaluateBinaryTypeTrait(*this, BTT, LhsT, RhsT, KWLoc);
 
-  // Select trait result type.
-  QualType ResultType;
-  switch (BTT) {
-  case BTT_IsBaseOf:       ResultType = Context.BoolTy; break;
-  case BTT_IsConvertible:  ResultType = Context.BoolTy; break;
-  case BTT_IsSame:         ResultType = Context.BoolTy; break;
-  case BTT_TypeCompatible: ResultType = Context.IntTy; break;
-  case BTT_IsConvertibleTo: ResultType = Context.BoolTy; break;
-  case BTT_IsTriviallyAssignable: ResultType = Context.BoolTy;
-  }
+  QualType ResultType = Context.BoolTy;
+  // __builtin_types_compatible_p is a GNU C extension, not a C++ type trait.
+  if (BTT == BTT_TypeCompatible)
+    ResultType = Context.IntTy;
 
   return Owned(new (Context) BinaryTypeTraitExpr(KWLoc, BTT, LhsTSInfo,
                                                  RhsTSInfo, Value, RParen,