diff --git a/include/llvm/Target/TargetLowering.h b/include/llvm/Target/TargetLowering.h
index 0dc8836242d..590de20dc81 100644
--- a/include/llvm/Target/TargetLowering.h
+++ b/include/llvm/Target/TargetLowering.h
@@ -35,6 +35,8 @@ namespace llvm {
   class SDNode;
   class SDOperand;
   class SelectionDAG;
+  class MachineBasicBlock;
+  class MachineInstr;
 
 //===----------------------------------------------------------------------===//
 /// TargetLowering - This class defines information used to lower LLVM code to