diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index 7486371474..2f682cd69e 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,7 @@
+2012-12-18  Pierre Muller  <muller@sourceware.org>
+
+	* ui-file.h (tee_file_new): Add extern modifier in header declaration.
+
 2012-12-20  Tom Tromey  <tromey@redhat.com>
 
 	* serial.c (deprecated_serial_fd): Remove.
diff --git a/gdb/ui-file.h b/gdb/ui-file.h
index bb85713477..7385dfd70c 100644
--- a/gdb/ui-file.h
+++ b/gdb/ui-file.h
@@ -135,8 +135,8 @@ extern struct ui_file *gdb_fopen (char *name, char *mode);
 /* Create a file which writes to both ONE and TWO.  CLOSE_ONE
    and CLOSE_TWO indicate whether the original files should be
    closed when the new file is closed.  */
-struct ui_file *tee_file_new (struct ui_file *one,
-			      int close_one,
-			      struct ui_file *two,
-			      int close_two);
+extern struct ui_file *tee_file_new (struct ui_file *one,
+				     int close_one,
+				     struct ui_file *two,
+				     int close_two);
 #endif