diff --git a/clang/lib/Sema/SemaDecl.cpp b/clang/lib/Sema/SemaDecl.cpp
index c8c3815..0244d4c 100644
--- a/clang/lib/Sema/SemaDecl.cpp
+++ b/clang/lib/Sema/SemaDecl.cpp
@@ -9300,7 +9300,7 @@
   // Static locals inherit dll attributes from their function.
   if (VD->isStaticLocal()) {
     if (FunctionDecl *FD =
-            dyn_cast<FunctionDecl>(VD->getParentFunctionOrMethod())) {
+            dyn_cast_or_null<FunctionDecl>(VD->getParentFunctionOrMethod())) {
       if (Attr *A = getDLLAttr(FD)) {
         auto *NewAttr = cast<InheritableAttr>(A->clone(getASTContext()));
         NewAttr->setInherited(true);