diff --git a/include/Support/STLExtras.h b/include/Support/STLExtras.h
index 4112b1f5ec5..b2fde436372 100644
--- a/include/Support/STLExtras.h
+++ b/include/Support/STLExtras.h
@@ -11,6 +11,7 @@
 #define LLVM_SUPPORT_STL_EXTRAS_H
 
 #include <functional>
+#include "Support/iterator"
 
 //===----------------------------------------------------------------------===//
 //     Extra additions to <functional>
diff --git a/include/llvm/ADT/STLExtras.h b/include/llvm/ADT/STLExtras.h
index 4112b1f5ec5..b2fde436372 100644
--- a/include/llvm/ADT/STLExtras.h
+++ b/include/llvm/ADT/STLExtras.h
@@ -11,6 +11,7 @@
 #define LLVM_SUPPORT_STL_EXTRAS_H
 
 #include <functional>
+#include "Support/iterator"
 
 //===----------------------------------------------------------------------===//
 //     Extra additions to <functional>