diff --git a/kernel/user.c b/kernel/user.c
index e91331c..0f3aa02 100644
--- a/kernel/user.c
+++ b/kernel/user.c
@@ -129,7 +129,7 @@
 }
 
 /* return cpu shares held by the user */
-ssize_t cpu_shares_show(struct kset *kset, char *buffer)
+static ssize_t cpu_shares_show(struct kset *kset, char *buffer)
 {
 	struct user_struct *up = container_of(kset, struct user_struct, kset);
 
@@ -137,7 +137,8 @@
 }
 
 /* modify cpu shares held by the user */
-ssize_t cpu_shares_store(struct kset *kset, const char *buffer, size_t size)
+static ssize_t cpu_shares_store(struct kset *kset, const char *buffer,
+				size_t size)
 {
 	struct user_struct *up = container_of(kset, struct user_struct, kset);
 	unsigned long shares;