diff --git a/lib/Transforms/Utils/ModuleUtils.cpp b/lib/Transforms/Utils/ModuleUtils.cpp
index c84beceee19..1ef3757017a 100644
--- a/lib/Transforms/Utils/ModuleUtils.cpp
+++ b/lib/Transforms/Utils/ModuleUtils.cpp
@@ -73,7 +73,7 @@ static void appendToUsedList(Module &M, StringRef Name, ArrayRef<GlobalValue *>
   SmallPtrSet<Constant *, 16> InitAsSet;
   SmallVector<Constant *, 16> Init;
   if (GV) {
-    ConstantArray *CA = dyn_cast<ConstantArray>(GV->getInitializer());
+    auto *CA = cast<ConstantArray>(GV->getInitializer());
     for (auto &Op : CA->operands()) {
       Constant *C = cast_or_null<Constant>(Op);
       if (InitAsSet.insert(C).second)