diff --git a/include/linux/compat.h b/include/linux/compat.h
index dda1697..9760753 100644
--- a/include/linux/compat.h
+++ b/include/linux/compat.h
@@ -226,5 +226,7 @@
 
 asmlinkage long compat_sys_adjtimex(struct compat_timex __user *utp);
 
+extern int compat_printk(const char *fmt, ...);
+
 #endif /* CONFIG_COMPAT */
 #endif /* _LINUX_COMPAT_H */