diff --git a/clang/lib/Sema/SemaOverload.cpp b/clang/lib/Sema/SemaOverload.cpp
index f4ec04a..a5a51d5 100644
--- a/clang/lib/Sema/SemaOverload.cpp
+++ b/clang/lib/Sema/SemaOverload.cpp
@@ -9984,7 +9984,7 @@
           DeductionFailure.getFirstArg()->getNonTypeTemplateArgumentType();
       QualType T2 =
           DeductionFailure.getSecondArg()->getNonTypeTemplateArgumentType();
-      if (!S.Context.hasSameType(T1, T2)) {
+      if (!T1.isNull() && !T2.isNull() && !S.Context.hasSameType(T1, T2)) {
         S.Diag(Templated->getLocation(),
                diag::note_ovl_candidate_inconsistent_deduction_types)
           << ParamD->getDeclName() << *DeductionFailure.getFirstArg() << T1