diff --git a/kmod/src/acl.c b/kmod/src/acl.c
index d0fef58e..0fdb9d93 100644
--- a/kmod/src/acl.c
+++ b/kmod/src/acl.c
@@ -253,7 +253,9 @@ int scoutfs_acl_get_xattr(struct dentry *dentry, const char *name, void *value,
 }
 
 #ifdef KC_XATTR_STRUCT_XATTR_HANDLER
-int scoutfs_acl_set_xattr(const struct xattr_handler *handler, struct dentry *dentry,
+int scoutfs_acl_set_xattr(const struct xattr_handler *handler,
+			  KC_VFS_NS_DEF
+			  struct dentry *dentry,
 			  struct inode *inode, const char *name, const void *value,
 			  size_t size, int flags)
 {
diff --git a/kmod/src/acl.h b/kmod/src/acl.h
index 1712b7e8..e7f983e6 100644
--- a/kmod/src/acl.h
+++ b/kmod/src/acl.h
@@ -10,7 +10,9 @@ int scoutfs_set_acl_locked(struct inode *inode, struct posix_acl *acl, int type,
 int scoutfs_acl_get_xattr(const struct xattr_handler *, struct dentry *dentry,
 			  struct inode *inode, const char *name, void *value,
 			  size_t size);
-int scoutfs_acl_set_xattr(const struct xattr_handler *, struct dentry *dentry,
+int scoutfs_acl_set_xattr(const struct xattr_handler *,
+			  KC_VFS_NS_DEF
+			  struct dentry *dentry,
 			  struct inode *inode, const char *name, const void *value,
 			  size_t size, int flags);
 #else
diff --git a/kmod/src/xattr.c b/kmod/src/xattr.c
index a13f3d19..09db9927 100644
--- a/kmod/src/xattr.c
+++ b/kmod/src/xattr.c
@@ -1026,7 +1026,9 @@ static int scoutfs_xattr_get_handler
 
 static int scoutfs_xattr_set_handler
 #ifdef KC_XATTR_STRUCT_XATTR_HANDLER
-		(const struct xattr_handler *handler, struct dentry *dentry,
+		(const struct xattr_handler *handler,
+		 KC_VFS_NS_DEF
+		 struct dentry *dentry,
 		 struct inode *inode, const char *name, const void *value,
 		 size_t size, int flags)
 {