diff --git a/lib/Transforms/Utils/LoopUnrollRuntime.cpp b/lib/Transforms/Utils/LoopUnrollRuntime.cpp
index 91438c9..d43ce7a 100644
--- a/lib/Transforms/Utils/LoopUnrollRuntime.cpp
+++ b/lib/Transforms/Utils/LoopUnrollRuntime.cpp
@@ -762,7 +762,7 @@
                            cast<BasicBlock>(VMap[Phi->getIncomingBlock(i)]));
      }
    }
-#ifdef EXPENSIVE_CHECKS
+#if defined(EXPENSIVE_CHECKS) && !defined(NDEBUG)
     for (BasicBlock *SuccBB : successors(BB)) {
       assert(!(any_of(OtherExits,
                       [SuccBB](BasicBlock *EB) { return EB == SuccBB; }) ||