diff --git a/os/macosx/macos.h b/os/macosx/macos.h
index 491f4ff090..ac17801128 100644
--- a/os/macosx/macos.h
+++ b/os/macosx/macos.h
@@ -1,3 +1,5 @@
+/* $Id$ */
+
 #ifndef MACOS_H
 #define MACOS_H
 
diff --git a/os/macosx/macos.m b/os/macosx/macos.m
index d61900bb18..c09e58de10 100644
--- a/os/macosx/macos.m
+++ b/os/macosx/macos.m
@@ -1,3 +1,5 @@
+/* $Id$ */
+
 #include <AppKit/AppKit.h>
 
 /*
diff --git a/os/macosx/splash.c b/os/macosx/splash.c
index 99791cc21c..2d4373ce57 100644
--- a/os/macosx/splash.c
+++ b/os/macosx/splash.c
@@ -1,3 +1,4 @@
+/* $Id$ */
 
 #include "../../stdafx.h"
 #include "../../openttd.h"
diff --git a/os/macosx/splash.h b/os/macosx/splash.h
index 7454ccaa03..39880562d4 100644
--- a/os/macosx/splash.h
+++ b/os/macosx/splash.h
@@ -1,3 +1,4 @@
+/* $Id$ */
 
 #ifndef SPLASH_H
 #define SPLASH_H