diff --git a/fs/overlayfs/overlayfs.h b/fs/overlayfs/overlayfs.h
index 59ee6ba79ee88..1c0ad84646e86 100644
--- a/fs/overlayfs/overlayfs.h
+++ b/fs/overlayfs/overlayfs.h
@@ -28,7 +28,9 @@ enum ovl_path_type {
 
 #define OVL_XATTR_NAMESPACE "overlay."
 #define OVL_XATTR_TRUSTED_PREFIX XATTR_TRUSTED_PREFIX OVL_XATTR_NAMESPACE
+#define OVL_XATTR_TRUSTED_PREFIX_LEN (sizeof(OVL_XATTR_TRUSTED_PREFIX) - 1)
 #define OVL_XATTR_USER_PREFIX XATTR_USER_PREFIX OVL_XATTR_NAMESPACE
+#define OVL_XATTR_USER_PREFIX_LEN (sizeof(OVL_XATTR_USER_PREFIX) - 1)
 
 enum ovl_xattr {
 	OVL_XATTR_OPAQUE,
diff --git a/fs/overlayfs/xattrs.c b/fs/overlayfs/xattrs.c
index 8e7e4ca62448b..d20032f8a5373 100644
--- a/fs/overlayfs/xattrs.c
+++ b/fs/overlayfs/xattrs.c
@@ -10,10 +10,10 @@ bool ovl_is_private_xattr(struct super_block *sb, const char *name)
 
 	if (ofs->config.userxattr)
 		return strncmp(name, OVL_XATTR_USER_PREFIX,
-			       sizeof(OVL_XATTR_USER_PREFIX) - 1) == 0;
+			       OVL_XATTR_USER_PREFIX_LEN) == 0;
 	else
 		return strncmp(name, OVL_XATTR_TRUSTED_PREFIX,
-			       sizeof(OVL_XATTR_TRUSTED_PREFIX) - 1) == 0;
+			       OVL_XATTR_TRUSTED_PREFIX_LEN) == 0;
 }
 
 static int ovl_xattr_set(struct dentry *dentry, struct inode *inode, const char *name,