diff --git a/lib/Target/SystemZ/SystemZISelLowering.cpp b/lib/Target/SystemZ/SystemZISelLowering.cpp
index d69f578..e0ca9da 100644
--- a/lib/Target/SystemZ/SystemZISelLowering.cpp
+++ b/lib/Target/SystemZ/SystemZISelLowering.cpp
@@ -847,7 +847,7 @@
   }
 
   if (isa<LoadInst>(I) && I->hasOneUse()) {
-    auto *SingleUser = dyn_cast<Instruction>(*I->user_begin());
+    auto *SingleUser = cast<Instruction>(*I->user_begin());
     if (SingleUser->getParent() == I->getParent()) {
       if (isa<ICmpInst>(SingleUser)) {
         if (auto *C = dyn_cast<ConstantInt>(SingleUser->getOperand(1)))