diff --git a/include/cutils/android_reboot.h b/include/cutils/android_reboot.h
index 8c30e8e3f..85e1b7e5b 100644
--- a/include/cutils/android_reboot.h
+++ b/include/cutils/android_reboot.h
@@ -27,7 +27,7 @@ __BEGIN_DECLS
 /* Properties */
 #define ANDROID_RB_PROPERTY "sys.powerctl"
 
-int android_reboot(int cmd, int flags, char *arg);
+int android_reboot(int cmd, int flags, const char *arg);
 
 __END_DECLS
 
diff --git a/libcutils/android_reboot.c b/libcutils/android_reboot.c
index aa8620616..6ae23c1f0 100644
--- a/libcutils/android_reboot.c
+++ b/libcutils/android_reboot.c
@@ -89,7 +89,7 @@ static void remount_ro(void)
 }
 
 
-int android_reboot(int cmd, int flags UNUSED, char *arg)
+int android_reboot(int cmd, int flags UNUSED, const char *arg)
 {
     int ret;