diff --git a/libcxx/src/iostream.cpp b/libcxx/src/iostream.cpp
--- a/libcxx/src/iostream.cpp
+++ b/libcxx/src/iostream.cpp
@@ -7,7 +7,7 @@
 //===----------------------------------------------------------------------===//
 
 #include <__locale>
-#include "__std_stream"
+#include "std_stream.cpp"
 #include <new>
 #include <string>
 
diff --git a/libcxx/src/__std_stream b/libcxx/src/std_stream.h
rename from libcxx/src/__std_stream
rename to libcxx/src/std_stream.h
--- a/libcxx/src/__std_stream
+++ b/libcxx/src/std_stream.h
@@ -7,8 +7,8 @@
 //
 //===----------------------------------------------------------------------===//
 
-#ifndef _LIBCPP___STD_STREAM
-#define _LIBCPP___STD_STREAM
+#ifndef _LIBCPP_STD_STREAM_H
+#define _LIBCPP_STD_STREAM_H
 
 #include <__config>
 #include <__locale>
@@ -358,4 +358,4 @@
 
 _LIBCPP_POP_MACROS
 
-#endif // _LIBCPP___STD_STREAM
+#endif // _LIBCPP_STD_STREAM_H
diff --git a/libcxx/utils/data/ignore_format.txt b/libcxx/utils/data/ignore_format.txt
--- a/libcxx/utils/data/ignore_format.txt
+++ b/libcxx/utils/data/ignore_format.txt
@@ -805,7 +805,7 @@
 libcxx/src/regex.cpp
 libcxx/src/shared_mutex.cpp
 libcxx/src/stdexcept.cpp
-libcxx/src/__std_stream
+libcxx/src/std_stream.h
 libcxx/src/string.cpp
 libcxx/src/strstream.cpp
 libcxx/src/support/ibm/mbsnrtowcs.cpp