diff --git a/src/Changelog/Formatter/AddTopFormatter.php b/src/Changelog/Formatter/AddTopFormatter.php
index 7aab5cc..c74114e 100644
--- a/src/Changelog/Formatter/AddTopFormatter.php
+++ b/src/Changelog/Formatter/AddTopFormatter.php
@@ -69,6 +69,6 @@ public function updateExistingLines(
 
     public function getLastVersionRegex(): string
     {
-        return '#.*#';
+        return '#(\d+\.\d+\.\d+.*)#';
     }
 }
diff --git a/src/Changelog/Formatter/PrefixGroupFormatter.php b/src/Changelog/Formatter/PrefixGroupFormatter.php
index 3af142b..f458c44 100644
--- a/src/Changelog/Formatter/PrefixGroupFormatter.php
+++ b/src/Changelog/Formatter/PrefixGroupFormatter.php
@@ -102,7 +102,7 @@ public function updateExistingLines(
 
     public function getLastVersionRegex(): string
     {
-        return '#.*#';
+        return '/\[(\d+\.\d+\.\d+.*)\]/';
     }
 
     private function getFormattedDate(): string