diff --git a/phpstan.neon b/phpstan.neon
index b95427a..ef6cdd2 100644
--- a/phpstan.neon
+++ b/phpstan.neon
@@ -11,9 +11,6 @@ parameters:
     paths:
         - src
 
-    scanDirectories:
-        - /usr/share/icinga-php
-
     ignoreErrors:
         -
             messages:
diff --git a/src/BaseFilter.php b/src/BaseFilter.php
index 267decb..e24f514 100644
--- a/src/BaseFilter.php
+++ b/src/BaseFilter.php
@@ -32,11 +32,11 @@ public function getBaseFilter()
     /**
      * Set the base filter
      *
-     * @param Rule $baseFilter
+     * @param ?Rule $baseFilter
      *
      * @return $this
      */
-    public function setBaseFilter(Rule $baseFilter = null): self
+    public function setBaseFilter(?Rule $baseFilter = null): self
     {
         $this->baseFilter = $baseFilter;
 
diff --git a/src/Filter.php b/src/Filter.php
index 3bbdd36..c5f7902 100644
--- a/src/Filter.php
+++ b/src/Filter.php
@@ -536,11 +536,7 @@ protected function performMatch(Rule $rule, $row)
      */
     protected function extractValue($column, $row)
     {
-        try {
-            return $row->{$column};
-        } catch (Throwable $_) {
-            return null;
-        }
+        return $row->$column ?? null;
     }
 
     /**
diff --git a/src/PriorityQueue.php b/src/PriorityQueue.php
index 1992ec5..2c3f448 100644
--- a/src/PriorityQueue.php
+++ b/src/PriorityQueue.php
@@ -25,9 +25,9 @@ class PriorityQueue extends SplPriorityQueue
      * @param TValue $value
      * @param TPriority $priority
      *
-     * @return bool
+     * @return true
      */
-    public function insert($value, $priority): bool
+    public function insert($value, $priority): true
     {
         return parent::insert($value, [$priority, $this->serial--]);
     }
diff --git a/src/Str.php b/src/Str.php
index b1cd19c..b48663a 100644
--- a/src/Str.php
+++ b/src/Str.php
@@ -76,7 +76,7 @@ public static function symmetricSplit(?string $subject, string $delimiter, int $
      *
      * @return array<string>
      */
-    public static function trimSplit(?string $subject, string $delimiter = ',', int $limit = null)
+    public static function trimSplit(?string $subject, string $delimiter = ',', ?int $limit = null)
     {
         if ($subject === null || empty($delimiter)) {
             return [];