diff --git a/include/fs/fs_interface.h b/include/fs/fs_interface.h
index 42bbd1133bf..283e1cbcd41 100644
--- a/include/fs/fs_interface.h
+++ b/include/fs/fs_interface.h
@@ -13,9 +13,16 @@ extern "C" {
 
 #if defined(CONFIG_FILE_SYSTEM_LITTLEFS)
 #define MAX_FILE_NAME 256
-#else /* FAT_FS */
+#elif defined(CONFIG_FAT_FILESYSTEM_ELM)
+#if defined(CONFIG_FS_FATFS_LFN)
+#define MAX_FILE_NAME CONFIG_FS_FATFS_MAX_LFN
+#else /* CONFIG_FS_FATFS_LFN */
 #define MAX_FILE_NAME 12 /* Uses 8.3 SFN */
-#endif
+#endif /* CONFIG_FS_FATFS_LFN */
+#else /* filesystem selection */
+/* Use standard 8.3 when no filesystem is explicitly selected */
+#define MAX_FILE_NAME 12
+#endif /* filesystem selection */
 
 struct fs_mount_t;