diff --git a/fs/drop_caches.c b/fs/drop_caches.c
index 59375ef..e2c6b65 100644
--- a/fs/drop_caches.c
+++ b/fs/drop_caches.c
@@ -25,7 +25,7 @@
 	spin_unlock(&inode_lock);
 }
 
-void drop_pagecache(void)
+static void drop_pagecache(void)
 {
 	struct super_block *sb;
 
@@ -45,7 +45,7 @@
 	spin_unlock(&sb_lock);
 }
 
-void drop_slab(void)
+static void drop_slab(void)
 {
 	int nr_objects;
 
diff --git a/include/linux/mm.h b/include/linux/mm.h
index 8b7f4a5..fef602d 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -1230,8 +1230,6 @@
 					void __user *, size_t *, loff_t *);
 unsigned long shrink_slab(unsigned long scanned, gfp_t gfp_mask,
 			unsigned long lru_pages);
-void drop_pagecache(void);
-void drop_slab(void);
 
 #ifndef CONFIG_MMU
 #define randomize_va_space 0