diff --git a/include/llvm/BinaryFormat/XCOFF.h b/include/llvm/BinaryFormat/XCOFF.h
index f10fcb7b2a6..f09938a5788 100644
--- a/include/llvm/BinaryFormat/XCOFF.h
+++ b/include/llvm/BinaryFormat/XCOFF.h
@@ -13,10 +13,11 @@
 #ifndef LLVM_BINARYFORMAT_XCOFF_H
 #define LLVM_BINARYFORMAT_XCOFF_H
 
-#include "llvm/ADT/StringRef.h"
 #include <cstdint>
 
 namespace llvm {
+class StringRef;
+
 namespace XCOFF {
 
 // Constants used in the XCOFF definition.
diff --git a/lib/BinaryFormat/XCOFF.cpp b/lib/BinaryFormat/XCOFF.cpp
index fe98f5c044a..3c8a2cdbc3a 100644
--- a/lib/BinaryFormat/XCOFF.cpp
+++ b/lib/BinaryFormat/XCOFF.cpp
@@ -7,6 +7,7 @@
 //===----------------------------------------------------------------------===//
 
 #include "llvm/BinaryFormat/XCOFF.h"
+#include "llvm/ADT/StringRef.h"
 
 using namespace llvm;