diff --git a/src/Config/Filters.php b/src/Config/Filters.php
index 772e45b..0580549 100644
--- a/src/Config/Filters.php
+++ b/src/Config/Filters.php
@@ -153,7 +153,7 @@ private function getBaseLineData(): array
     }
 
     /**
-     * @return array{0: string, 1: string|int}
+     * @return array{0: string, 1: string|int|null}
      */
     private function handleTags(string|int|TaggedValue $value): array
     {
@@ -168,6 +168,10 @@ private function handleTags(string|int|TaggedValue $value): array
             $value = (string) $value->getValue();
         }
 
+        if ($value === 'null') {
+            $value = null;
+        }
+
         return [$operator, $value];
     }
 }