diff --git a/include/romfs_dev.h b/include/romfs_dev.h
index 39bbed0..6f555a6 100644
--- a/include/romfs_dev.h
+++ b/include/romfs_dev.h
@@ -13,7 +13,8 @@
 
 /// RomFS header.
 typedef struct {
-    uint64_t headerSize;        ///< Size of the header.
+    uint32_t headerMagic;       ///< Magic value.
+    uint32_t headerSize;        ///< Size of the header.
     uint64_t dirHashTableOff;   ///< Offset of the directory hash table.
     uint64_t dirHashTableSize;  ///< Size of the directory hash table.
     uint64_t dirTableOff;       ///< Offset of the directory table.
diff --git a/source/romfs_dev.c b/source/romfs_dev.c
index 8e90f70..35e8242 100644
--- a/source/romfs_dev.c
+++ b/source/romfs_dev.c
@@ -286,6 +286,10 @@ int32_t romfsMountCommon(const char *name, romfs_mount *mount) {
         goto fail_io;
     }
 
+    if (memcmp(&mount->header.headerMagic, "WUHB", sizeof(mount->header.headerMagic)) != 0) {
+        goto fail_io;
+    }
+
     if (mount->header.headerSize != 0x50) {
         goto fail_io;
     }