diff --git a/cmdline/app.h b/cmdline/app.h
index c4935455..751c7d6c 100644
--- a/cmdline/app.h
+++ b/cmdline/app.h
@@ -76,7 +76,7 @@ struct fssnapshot_struct {
 	/**
 	 * Root directory of the volume/dataset mountpoint.
 	 * It ALWAYS terminates with /
-	 * - Btrfs/Bcachefs: subvolume root
+	 * - Btrfs/Bcachefs: subvolume root (canonical path via realpath)
 	 * - ZFS: dataset mountpoint (canonical path via realpath)
 	 * - Windows: volume mountpoint (via GetVolumePathName)
 	 */
@@ -97,8 +97,8 @@ struct fssnapshot_struct {
 	 * It NEVER starts with '/'.
 	 * It is empty if the configured data directory is exactly root_dir.
 	 * If non-empty, it ALWAYS terminates with '/'.
-	 * - ZFS: relative suffix computed from realpath() canonical representation
-	 * - Btrfs/Bcachefs/Windows: relative suffix computed from configured path
+	 * - Unix: relative suffix computed from the realpath() canonical representation
+	 * - Windows: relative suffix computed from the configured path
 	 */
 	char sub_dir[PATH_MAX];
 
diff --git a/cmdline/unixapp.c b/cmdline/unixapp.c
index 7a57323b..3044a51b 100644
--- a/cmdline/unixapp.c
+++ b/cmdline/unixapp.c
@@ -2144,9 +2144,14 @@ int fsinfo(const char* path, int* has_persistent_inode, int* has_syncronized_har
 #if HAVE_LINUX_DEVICE
 static int fssnapshot_inode(const char* path, uint32_t magic, uint64_t root_inode, struct fssnapshot_struct* fss)
 {
+	char resolved[PATH_MAX];
 	char current_path[PATH_MAX];
 
-	pathcpy(current_path, sizeof(current_path), path);
+	if (realpath(path, resolved) == 0)
+		return -1;
+
+	pathslash(resolved, sizeof(resolved));
+	pathcpy(current_path, sizeof(current_path), resolved);
 
 	/* walk up the directory tree to find the subvolume root (Inode 256) */
 	while (1) {
@@ -2172,7 +2177,13 @@ static int fssnapshot_inode(const char* path, uint32_t magic, uint64_t root_inod
 			}
 
 			size_t root_len = strlen(fss->root_dir);
-			pathcpy(fss->sub_dir, sizeof(fss->sub_dir), path + root_len);
+
+			if (pathncmp(fss->root_dir, resolved, root_len) != 0) {
+				errno = EINVAL;
+				return -1;
+			}
+
+			pathcpy(fss->sub_dir, sizeof(fss->sub_dir), resolved + root_len);
 
 			fss->magic = magic;
 			return 0;