1 files changed, 6 insertions, 3 deletions
diff --git a/clang/lib/Sema/SemaTemplateDeductionGuide.cpp b/clang/lib/Sema/SemaTemplateDeductionGuide.cpp
index 3d54d1e..fe673ea 100644
--- a/clang/lib/Sema/SemaTemplateDeductionGuide.cpp
+++ b/clang/lib/Sema/SemaTemplateDeductionGuide.cpp
@@ -1428,10 +1428,13 @@ void Sema::DeclareImplicitDeductionGuides(TemplateDecl *Template,
     DeclareImplicitDeductionGuidesForTypeAlias(*this, AliasTemplate, Loc);
     return;
   }
-  if (CXXRecordDecl *DefRecord =
-          cast<CXXRecordDecl>(Template->getTemplatedDecl())->getDefinition()) {
+  CXXRecordDecl *DefRecord =
+      dyn_cast_or_null<CXXRecordDecl>(Template->getTemplatedDecl());
+  if (!DefRecord)
+    return;
+  if (const CXXRecordDecl *Definition = DefRecord->getDefinition()) {
     if (TemplateDecl *DescribedTemplate =
-            DefRecord->getDescribedClassTemplate())
+            Definition->getDescribedClassTemplate())
       Template = DescribedTemplate;
   }