diff --git a/llvm/include/llvm/CodeGen/MachinePipeliner.h b/llvm/include/llvm/CodeGen/MachinePipeliner.h
--- a/llvm/include/llvm/CodeGen/MachinePipeliner.h
+++ b/llvm/include/llvm/CodeGen/MachinePipeliner.h
@@ -40,6 +40,7 @@
 #ifndef LLVM_CODEGEN_MACHINEPIPELINER_H
 #define LLVM_CODEGEN_MACHINEPIPELINER_H
 
+#include "llvm/ADT/SetVector.h"
 #include "llvm/CodeGen/MachineDominators.h"
 #include "llvm/CodeGen/MachineOptimizationRemarkEmitter.h"
 #include "llvm/CodeGen/RegisterClassInfo.h"