diff --git a/include/llvm/CodeGen/Passes.h b/include/llvm/CodeGen/Passes.h
index 206bc2e1236..b0de2dc632a 100644
--- a/include/llvm/CodeGen/Passes.h
+++ b/include/llvm/CodeGen/Passes.h
@@ -24,6 +24,7 @@ namespace llvm {
   class FunctionPass;
   class MachineFunctionPass;
   class PassInfo;
+  class PassManagerBase;
   class TargetLowering;
   class TargetRegisterClass;
   class raw_ostream;