diff --git a/clang/lib/Sema/SemaStmt.cpp b/clang/lib/Sema/SemaStmt.cpp
index e1b1a47..d734416 100644
--- a/clang/lib/Sema/SemaStmt.cpp
+++ b/clang/lib/Sema/SemaStmt.cpp
@@ -3066,22 +3066,23 @@
   //  has multiple return statements, the return type is deduced for each return
   //  statement. [...] if the type deduced is not the same in each deduction,
   //  the program is ill-formed.
-  if (AT->isDeduced() && !FD->isInvalidDecl()) {
+  QualType DeducedT = AT->getDeducedType();
+  if (!DeducedT.isNull() && !FD->isInvalidDecl()) {
     AutoType *NewAT = Deduced->getContainedAutoType();
     CanQualType OldDeducedType = Context.getCanonicalFunctionResultType(
-                                   AT->getDeducedType());
+                                   DeducedT);
     CanQualType NewDeducedType = Context.getCanonicalFunctionResultType(
                                    NewAT->getDeducedType());
     if (!FD->isDependentContext() && OldDeducedType != NewDeducedType) {
       const LambdaScopeInfo *LambdaSI = getCurLambda();
       if (LambdaSI && LambdaSI->HasImplicitReturnType) {
         Diag(ReturnLoc, diag::err_typecheck_missing_return_type_incompatible)
-          << NewAT->getDeducedType() << AT->getDeducedType()
+          << NewAT->getDeducedType() << DeducedT
           << true /*IsLambda*/;
       } else {
         Diag(ReturnLoc, diag::err_auto_fn_different_deductions)
           << (AT->isDecltypeAuto() ? 1 : 0)
-          << NewAT->getDeducedType() << AT->getDeducedType();
+          << NewAT->getDeducedType() << DeducedT;
       }
       return true;
     }