diff --git a/include/llvm/Transforms/Utils/PromoteMemToReg.h b/include/llvm/Transforms/Utils/PromoteMemToReg.h
index 98d51a29ad7..0bb6ec69bbd 100644
--- a/include/llvm/Transforms/Utils/PromoteMemToReg.h
+++ b/include/llvm/Transforms/Utils/PromoteMemToReg.h
@@ -21,7 +21,6 @@ namespace llvm {
 
 class AllocaInst;
 class DominatorTree;
-class DominanceFrontier;
 class AliasSetTracker;
 
 /// isAllocaPromotable - Return true if this alloca is legal for promotion.