diff --git a/bot.py b/bot.py
index ce31cd7..21cc457 100644
--- a/bot.py
+++ b/bot.py
@@ -22,16 +22,16 @@ async def on_message(message):
     if message.author == bot.user:
         return
 
-    # Check if the message contains "nixos" (case-insensitive, as a whole word, not in a URL)
-    if re.search(r'\bnixos\b', message.content, re.IGNORECASE):
-        # Replace "nixos" with "fagOS" (preserving case of the first letter), but exclude URLs
-        new_content = re.sub(
-            r'(?<!https?://\S*)\b(nixos)\b(?!\S*\/)',
-            lambda m: 'FagOS' if m.group(1)[0].isupper() else 'fagOS',
-            message.content,
-            flags=re.IGNORECASE
-        )
+    # Replace "nixos" with "fagOS" (preserving case of the first letter), but exclude URLs starting with http(s)://
+    new_content = re.sub(
+        r'(https?://\S+)|(\bnixos\b)',
+        lambda m: m.group(1) if m.group(1) else ('FagOS' if m.group(2)[0].isupper() else 'fagOS'),
+        message.content,
+        flags=re.IGNORECASE
+    )
 
+    # Only proceed if the content was actually modified
+    if new_content != message.content:
         # Get or create a webhook for impersonation
         webhooks = await message.channel.webhooks()
         webhook = next((w for w in webhooks if w.name == 'FagOSWebhook'), None)