diff --git a/modules/utils/subtitle_manager.py b/modules/utils/subtitle_manager.py
index d472a48..b260cb4 100644
--- a/modules/utils/subtitle_manager.py
+++ b/modules/utils/subtitle_manager.py
@@ -34,7 +34,7 @@ def get_srt(segments):
 
 
 def get_vtt(segments):
-    output = "WebVTT\n\n"
+    output = "WEBVTT\n\n"
     for i, segment in enumerate(segments):
         output += f"{timeformat_vtt(segment['start'])} --> {timeformat_vtt(segment['end'])}\n"
         if segment['text'].startswith(' '):
@@ -76,7 +76,7 @@ def parse_srt(file_path):
 
 
 def parse_vtt(file_path):
-    """Reads WebVTT file and returns as dict"""
+    """Reads WEBVTT file and returns as dict"""
     with open(file_path, 'r', encoding='utf-8') as file:
         webvtt_data = file.read()
 
@@ -84,7 +84,7 @@ def parse_vtt(file_path):
     blocks = webvtt_data.split('\n\n')
 
     for block in blocks:
-        if block.strip() != '' and not block.strip().startswith("WebVTT"):
+        if block.strip() != '' and not block.strip().startswith("WEBVTT"):
             lines = block.strip().split('\n')
             timestamp = lines[0]
             sentence = ' '.join(lines[1:])
@@ -107,7 +107,7 @@ def get_serialized_srt(dicts):
 
 
 def get_serialized_vtt(dicts):
-    output = "WebVTT\n\n"
+    output = "WEBVTT\n\n"
     for dic in dicts:
         output += f'{dic["timestamp"]}\n'
         output += f'{dic["sentence"]}\n\n'