diff --git a/constants.py b/constants.py
index 3936be0..736d286 100644
--- a/constants.py
+++ b/constants.py
@@ -8,9 +8,9 @@ lang_dict = {}
 
 def load_lang(lang):
     global lang_dict, default_lang_dict
-    with open("lang/en_US", "r") as f:
+    with open("lang/en_US.json", "r") as f:
         default_lang_dict = json.load(f)
-    with open(f"lang/{lang}", "r") as f:
+    with open(f"lang/{lang}.json", "r") as f:
         lang_dict = json.load(f)
 
 
diff --git a/lang/en_US b/lang/en_US.json
similarity index 98%
rename from lang/en_US
rename to lang/en_US.json
index e4549f1..db7a6af 100644
--- a/lang/en_US
+++ b/lang/en_US.json
@@ -4,8 +4,8 @@
         "added_tags_to_all": "Added tags <i>{tags}</i> to songs on the playlist.",
         "admin_help": "<h3>Admin command</h3>\n<b>Bot</b>\n<ul>\n<li><b>!<u>k</u>ill </b> - kill the bot</li>\n<li><b>!update </b> - update the bot</li>\n<li><b>!userban </b> {user}  - ban a user</li>\n<li><b>!userunban </b> {user}  - unban a user</li>\n<li><b>!urlbanlist </b>  - list banned url</li>\n<li><b>!urlban </b> [{url}]  - ban {url} (or current item's url by default) and remove this url from the library.</li>\n<li><b>!urlunban </b> {url}  - unban {url}</li>\n<li><b>!rescan </b> {url}  - rebuild local music file cache</li>\n<li><b>!dropdatabase</b> - clear the entire database, you will lose all settings and music library.</li>\n</ul>\n<b>Web Interface</b>\n<ul>\n<li><b>!<u>webuserlist</u></b> - list all users that have the permission of accessing the web interface, if auth mode is 'password'.</li>\n<li><b>!<u>webuseradd</u> {nick name}</b> - grant the user with {nick name} the access to the web interface, if auth mode is 'password'.</li>\n<li><b>!<u>webuserdel</u> {nick name}</b> - revoke the access to the web interface of {nick name}, if auth mode is 'password'.</li>\n<li><b>!update </b> - update the bot</li>\n<li><b>!userban </b> {user}  - ban a user</li>\n</ul>",
         "auto_paused": "Use <i>!play</i> to resume music!",
-        "bad_command": "{{command}}: command not found.",
-        "bad_parameter": "{command}: invalid parameter.",
+        "bad_command": "<i>{command}</i>: command not found.",
+        "bad_parameter": "<i>{command}</i>: invalid parameter.",
         "bad_url": "Bad URL requested.",
         "cache_refreshed": "Cache refreshed!",
         "change_ducking_volume": "Volume on ducking set to {volume} by {user}.",
diff --git a/lang/sync_translation.py b/lang/sync_translation.py
index 22fafba..67fb20b 100755
--- a/lang/sync_translation.py
+++ b/lang/sync_translation.py
@@ -39,30 +39,30 @@ def fetch_translation(r_client, r_secret):
         params = {'locale': lang_code,
                   'format': 'jsonnested'}
         r = requests.get(f"{base_url}/projects/{project_id}/exports", params=params, headers=headers)
-        with open(lang_code, "wb") as f:
+        with open(lang_code + ".json", "wb") as f:
             f.write(r.content)
 
 
 def push_strings(w_client, w_secret):
-    print("Pushing local en_US file into the remote host...")
+    print("Pushing local translation files into the remote host...")
     headers = get_access_header(w_client, w_secret)
 
     lang_files = os.listdir('.')
     lang_list = []
     for lang_file in lang_files:
-        match = re.search("[a-z]{2}_[A-Z]{2}", lang_file)
+        match = re.search("([a-z]{2}_[A-Z]{2})\.json", lang_file)
         if match:
-            lang_list.append(lang_file)
+            lang_list.append(match[1])
 
-    for lang_file in lang_list:
-        print(f" - Pushing {lang_file}")
+    for lang in lang_list:
+        print(f" - Pushing {lang}")
 
-        params = {'locale': lang_file,
+        params = {'locale': lang,
                   'format': 'jsonnested'}
-        files = {'file': open(lang_file, 'r')}
+        files = {'file': open(lang + ".json", 'r')}
 
         r = requests.post(f"{base_url}/projects/{project_id}/imports", params=params, headers=headers, files=files)
-        assert r.status_code == 200, f"Unable to push {lang_file} into remote host. {r.status_code}"
+        assert r.status_code == 200, f"Unable to push {lang} into remote host. {r.status_code}"
 
 
 if __name__ == "__main__":
diff --git a/util.py b/util.py
index c4723f1..6589881 100644
--- a/util.py
+++ b/util.py
@@ -419,9 +419,9 @@ def get_supported_language():
     lang_files = os.listdir('lang')
     lang_list = []
     for lang_file in lang_files:
-        match = re.search("[a-z]{2}_[A-Z]{2}", lang_file)
+        match = re.search("([a-z]{2}_[A-Z]{2})\.json", lang_file)
         if match:
-            lang_list.append(lang_file)
+            lang_list.append(match[1])
 
     return lang_list