diff --git a/clang/lib/Sema/SemaStmt.cpp b/clang/lib/Sema/SemaStmt.cpp
index f0d1947..16ed9ed 100644
--- a/clang/lib/Sema/SemaStmt.cpp
+++ b/clang/lib/Sema/SemaStmt.cpp
@@ -1409,7 +1409,11 @@
 
     void VisitDeclRefExpr(DeclRefExpr *E) {
       VarDecl *VD = dyn_cast<VarDecl>(E->getDecl());
-      if (!VD) return;
+      if (!VD) {
+        // Don't allow unhandled Decl types.
+        Simple = false;
+        return;
+      }
 
       Ranges.push_back(E->getSourceRange());