diff --git a/include/llvm/IR/IRBuilder.h b/include/llvm/IR/IRBuilder.h
index cdf840f5415..80a2ede4da1 100644
--- a/include/llvm/IR/IRBuilder.h
+++ b/include/llvm/IR/IRBuilder.h
@@ -90,6 +90,7 @@ public:
   void SetInsertPoint(Instruction *I) {
     BB = I->getParent();
     InsertPt = I;
+    assert(I != BB->end() && "Can't read debug loc from end()");
     SetCurrentDebugLocation(I->getDebugLoc());
   }