1 files changed, 2 insertions, 1 deletions
diff --git a/clang/lib/AST/ItaniumMangle.cpp b/clang/lib/AST/ItaniumMangle.cpp
index 2a2b491bcbd..66bccbe4584 100644
--- a/clang/lib/AST/ItaniumMangle.cpp
+++ b/clang/lib/AST/ItaniumMangle.cpp
@@ -1704,7 +1704,8 @@ void CXXNameMangler::mangleTemplateParamDecl(const NamedDecl *Decl) {
       QualType T = Tn->getType();
       if (Tn->isParameterPack()) {
         Out << "Tp";
-        T = T->castAs<PackExpansionType>()->getPattern();
+        if (auto *PackExpansion = T->getAs<PackExpansionType>())
+          T = PackExpansion->getPattern();
       }
       Out << "Tn";
       mangleType(T);