diff --git a/clang/lib/Sema/SemaTemplateDeduction.cpp b/clang/lib/Sema/SemaTemplateDeduction.cpp
--- a/clang/lib/Sema/SemaTemplateDeduction.cpp
+++ b/clang/lib/Sema/SemaTemplateDeduction.cpp
@@ -5804,10 +5804,10 @@
   }
 
   bool TraverseTemplateName(TemplateName Template) {
-    if (auto *TTP =
-            dyn_cast<TemplateTemplateParmDecl>(Template.getAsTemplateDecl()))
-      if (TTP->getDepth() == Depth)
-        Used[TTP->getIndex()] = true;
+    if (TemplateDecl *TD = Template.getAsTemplateDecl())
+      if (auto *TTP = dyn_cast<TemplateTemplateParmDecl>(TD))
+        if (TTP->getDepth() == Depth)
+          Used[TTP->getIndex()] = true;
     RecursiveASTVisitor<MarkUsedTemplateParameterVisitor>::
         TraverseTemplateName(Template);
     return true;