diff --git a/imap_filter/imap_filter.py b/imap_filter/imap_filter.py
index 911197b..25361dc 100644
--- a/imap_filter/imap_filter.py
+++ b/imap_filter/imap_filter.py
@@ -153,9 +153,9 @@ class ImapFilter:
                 condition = f'allof (header :contains "{field}" "{mfilter['regexp']}")'
             else:
                 condition = f'allof (header :contains "{field}" ["{'", "'.join(mfilter['words'])}"])'
-            search = f"^.*  # imap_filter: rule name 'imap_filter_INBOX_{mfilter['name']}'"
+            search = f"^.*  # imap_filter: rule name 'imap_filter_INBOX_{mfilter['name']}'$"
             replacement = f'if {condition} {{ fileinto "{mfilter['destination']}"; stop;}}  # imap_filter: rule name \'imap_filter_INBOX_{mfilter['name']}\''
-            match = re.search(search, content)
+            match = re.search(search, content, re.MULTILINE)
             if match:
                 self._log.debug(
                     "Line '%s' found in current file",