diff --git a/lib/Transforms/InstCombine/InstCombineCasts.cpp b/lib/Transforms/InstCombine/InstCombineCasts.cpp
index c782032..0c0864f 100644
--- a/lib/Transforms/InstCombine/InstCombineCasts.cpp
+++ b/lib/Transforms/InstCombine/InstCombineCasts.cpp
@@ -739,7 +739,7 @@
 }
 
 Instruction *InstCombiner::visitZExt(ZExtInst &CI) {
-  // If this zero extend is only used by a truncate, let the truncate by
+  // If this zero extend is only used by a truncate, let the truncate be
   // eliminated before we try to optimize this zext.
   if (CI.hasOneUse() && isa<TruncInst>(CI.use_back()))
     return 0;