diff --git a/lib/IR/Attributes.cpp b/lib/IR/Attributes.cpp
index bb98358a0ab..5de18272ffb 100644
--- a/lib/IR/Attributes.cpp
+++ b/lib/IR/Attributes.cpp
@@ -253,7 +253,7 @@ AttrBuilder::AttrBuilder(AttributeSet AS, unsigned Idx)
       break;
     }
 
-  assert(AWI && "Cannot find index in attribute set!");
+  if (!AWI) return;
 
   uint64_t Mask = AWI->Attrs.Raw();