diff --git a/include/llvm/Transforms/IPO.h b/include/llvm/Transforms/IPO.h
index 433621bacba..591fec1579c 100644
--- a/include/llvm/Transforms/IPO.h
+++ b/include/llvm/Transforms/IPO.h
@@ -15,6 +15,7 @@
 #ifndef LLVM_TRANSFORMS_IPO_H
 #define LLVM_TRANSFORMS_IPO_H
 
+#include "llvm/ADT/SmallVector.h"
 #include <functional>
 #include <vector>