diff --git a/block.c b/block.c
index cb57370..a77e8a0 100644
--- a/block.c
+++ b/block.c
@@ -1393,6 +1393,11 @@
     return 0;
 }
 
+static int bdrv_child_check_perm(BdrvChild *c, uint64_t perm, uint64_t shared,
+                                 GSList *ignore_children, Error **errp);
+static void bdrv_child_abort_perm_update(BdrvChild *c);
+static void bdrv_child_set_perm(BdrvChild *c, uint64_t perm, uint64_t shared);
+
 /*
  * Check whether permissions on this node can be changed in a way that
  * @cumulative_perms and @cumulative_shared_perms are the new cumulative
@@ -1615,8 +1620,8 @@
 
 /* Needs to be followed by a call to either bdrv_child_set_perm() or
  * bdrv_child_abort_perm_update(). */
-int bdrv_child_check_perm(BdrvChild *c, uint64_t perm, uint64_t shared,
-                          GSList *ignore_children, Error **errp)
+static int bdrv_child_check_perm(BdrvChild *c, uint64_t perm, uint64_t shared,
+                                 GSList *ignore_children, Error **errp)
 {
     int ret;
 
@@ -1627,7 +1632,7 @@
     return ret;
 }
 
-void bdrv_child_set_perm(BdrvChild *c, uint64_t perm, uint64_t shared)
+static void bdrv_child_set_perm(BdrvChild *c, uint64_t perm, uint64_t shared)
 {
     uint64_t cumulative_perms, cumulative_shared_perms;
 
@@ -1639,7 +1644,7 @@
     bdrv_set_perm(c->bs, cumulative_perms, cumulative_shared_perms);
 }
 
-void bdrv_child_abort_perm_update(BdrvChild *c)
+static void bdrv_child_abort_perm_update(BdrvChild *c)
 {
     bdrv_abort_perm_update(c->bs);
 }