diff --git a/clang/lib/AST/ByteCode/InterpBuiltin.cpp b/clang/lib/AST/ByteCode/InterpBuiltin.cpp
index 14f6929037ff5..ad923a52a4ce1 100644
--- a/clang/lib/AST/ByteCode/InterpBuiltin.cpp
+++ b/clang/lib/AST/ByteCode/InterpBuiltin.cpp
@@ -459,12 +459,13 @@ static bool interp__builtin_isinf(InterpState &S, CodePtr OpPC,
                                   const InterpFrame *Frame, bool CheckSign,
                                   const CallExpr *Call) {
   const Floating &Arg = S.Stk.pop<Floating>();
-  bool IsInf = Arg.isInf();
+  APFloat F = Arg.getAPFloat();
+  bool IsInf = F.isInfinity();
 
   if (CheckSign)
-    pushInteger(S, IsInf ? (Arg.isNegative() ? -1 : 1) : 0, Call->getType());
+    pushInteger(S, IsInf ? (F.isNegative() ? -1 : 1) : 0, Call->getType());
   else
-    pushInteger(S, Arg.isInf(), Call->getType());
+    pushInteger(S, IsInf, Call->getType());
   return true;
 }