diff --git a/llvm/include/llvm/CodeGen/PBQP/Graph.h b/llvm/include/llvm/CodeGen/PBQP/Graph.h
index 4a18ac5a06e7..b4e7fba68cb4 100644
--- a/llvm/include/llvm/CodeGen/PBQP/Graph.h
+++ b/llvm/include/llvm/CodeGen/PBQP/Graph.h
@@ -15,6 +15,7 @@
 #ifndef LLVM_CODEGEN_PBQP_GRAPH_H
 #define LLVM_CODEGEN_PBQP_GRAPH_H
 
+#include "llvm/ADT/STLExtras.h"
 #include "llvm/Support/Debug.h"
 #include <algorithm>
 #include <cassert>