diff --git a/llvm/include/llvm/Bitcode/Archive.h b/llvm/include/llvm/Bitcode/Archive.h
index 6a12ad1ef177..5b98c086be0a 100644
--- a/llvm/include/llvm/Bitcode/Archive.h
+++ b/llvm/include/llvm/Bitcode/Archive.h
@@ -19,12 +19,12 @@
 
 #include "llvm/ADT/ilist"
 #include "llvm/System/Path.h"
-#include "llvm/System/MappedFile.h"
 #include <map>
 #include <set>
 #include <fstream>
 
 namespace llvm {
+  namespace sys { class MappedFile; }
 
 // Forward declare classes
 class ModuleProvider;      // From VMCore