diff --git a/hlna.py b/hlna.py
index a334e84..a96f6be 100755
--- a/hlna.py
+++ b/hlna.py
@@ -502,7 +502,8 @@ def modextract(id_mod, id_game_workshop):
         modpath = f"../../../" + str({dir_shooter}) + "/Content/Mods/" + id_mod
         modpathlen = len(modpath)
         with open(f"{dir_ark_mods}.mod", "wb") as mod:
-            mod.write(struct.pack('<LLL{}sL{}sL'.format(modnamelen, modpathlen), int(id_mod), 0, modnamelen, modname, modpathlen, modpath, nummaps))
+            mod.write(struct.pack("<LLL%dsL%dsL" % (modnamelen, modpathlen),
+                                  int(modid), 0, modnamelen, modname, modpathlen, modpath, nummaps))
             for mapnum in range(nummaps):
                 mapfilelen = struct.unpack_from("<L", data, pos)[0]
                 mapfile = data[mapnamelen+12:mapnamelen+12+mapfilelen]