diff --git a/composer.json b/composer.json
index ecbbc1e..55d033c 100644
--- a/composer.json
+++ b/composer.json
@@ -20,7 +20,7 @@
     },
     "require-dev": {
         "phpunit/phpunit": "^9",
-        "phpstan/phpstan": "^0.12.91",
+        "phpstan/phpstan": "^1.3.3",
         "vimeo/psalm": "^4.8",
         "phpbench/phpbench": "^1.0",
         "squizlabs/php_codesniffer": "^3.6",
diff --git a/tests/Benchmark/CountIntersectionsBench.php b/tests/Benchmark/CountIntersectionsBench.php
index d5f8001..c26d6cd 100644
--- a/tests/Benchmark/CountIntersectionsBench.php
+++ b/tests/Benchmark/CountIntersectionsBench.php
@@ -1,4 +1,5 @@
 <?php
+
 declare(strict_types=1);
 
 namespace Danon\IntervalTree\Tests\Benchmark;
@@ -34,7 +35,7 @@ public function init(): void
         $this->bruteForceList = [];
 
         for ($i = 0; $i < self::AMOUNT_INTERVALS_IN_TREE; $i++) {
-            $interval = $this->generateInterval();
+            $interval = $this->generateInterval(self::MAX_INTERVAL_HIGH, self::MAX_INTERVAL_OFFSET);
             $this->tree->insert($interval);
             $this->bruteForceList[] = $interval;
         }
@@ -45,7 +46,7 @@ public function init(): void
      */
     public function benchTree(): void
     {
-        $searchedInterval = $this->generateInterval();
+        $searchedInterval = $this->generateInterval(self::MAX_INTERVAL_HIGH, self::MAX_INTERVAL_OFFSET);
         $this->tree->countIntersections($searchedInterval);
     }
 
@@ -54,7 +55,7 @@ public function benchTree(): void
      */
     public function benchBruteForce(): void
     {
-        $searchedInterval = $this->generateInterval();
+        $searchedInterval = $this->generateInterval(self::MAX_INTERVAL_HIGH, self::MAX_INTERVAL_OFFSET);
         foreach ($this->bruteForceList as $interval) {
             $interval->intersect($searchedInterval);
         }
diff --git a/tests/Benchmark/GenerateIntervalTrait.php b/tests/Benchmark/GenerateIntervalTrait.php
index 18a0fb1..7b81a77 100644
--- a/tests/Benchmark/GenerateIntervalTrait.php
+++ b/tests/Benchmark/GenerateIntervalTrait.php
@@ -1,25 +1,28 @@
 <?php
+
 declare(strict_types=1);
 
 namespace Danon\IntervalTree\Tests\Benchmark;
 
 use Danon\IntervalTree\Interval\NumericInterval;
 use Exception;
+use InvalidArgumentException;
 
 trait GenerateIntervalTrait
 {
     /**
+     * @param int $maxHigh
+     * @param int $maxOffset
      * @return NumericInterval
      */
-    private function generateInterval(): NumericInterval
+    private function generateInterval(int $maxHigh, int $maxOffset): NumericInterval
     {
         try {
-            $low = random_int(0, self::MAX_INTERVAL_HIGH);
-            $high = random_int($low, min($low + self::MAX_INTERVAL_OFFSET, self::MAX_INTERVAL_HIGH));
+            $low = random_int(0, $maxHigh);
+            $high = random_int($low, min($low + $maxOffset, $maxHigh));
         } catch (Exception $exception) {
-            echo 'Cannot generate interval: ' . $exception->getMessage();
-            exit;
+            throw new InvalidArgumentException('Wrong interval arguments', $exception->getCode(), $exception);
         }
         return new NumericInterval($low, $high);
     }
-}
\ No newline at end of file
+}
diff --git a/tests/Benchmark/HasIntersectionBench.php b/tests/Benchmark/HasIntersectionBench.php
index dbf1e18..5dfe650 100644
--- a/tests/Benchmark/HasIntersectionBench.php
+++ b/tests/Benchmark/HasIntersectionBench.php
@@ -1,11 +1,11 @@
 <?php
+
 declare(strict_types=1);
 
 namespace Danon\IntervalTree\Tests\Benchmark;
 
 use Danon\IntervalTree\Interval\NumericInterval;
 use Danon\IntervalTree\IntervalTree;
-use Exception;
 use PhpBench\Benchmark\Metadata\Annotations\Revs;
 
 /**
@@ -35,7 +35,7 @@ public function init(): void
         $this->bruteForceList = [];
 
         for ($i = 0; $i < self::AMOUNT_INTERVALS_IN_TREE; $i++) {
-            $interval = $this->generateInterval();
+            $interval = $this->generateInterval(self::MAX_INTERVAL_HIGH, self::MAX_INTERVAL_OFFSET);
             $this->tree->insert($interval);
             $this->bruteForceList[] = $interval;
         }
@@ -46,7 +46,7 @@ public function init(): void
      */
     public function benchTree(): void
     {
-        $searchedInterval = $this->generateInterval();
+        $searchedInterval = $this->generateInterval(self::MAX_INTERVAL_HIGH, self::MAX_INTERVAL_OFFSET);
         $this->tree->hasIntersection($searchedInterval);
     }
 
@@ -55,26 +55,11 @@ public function benchTree(): void
      */
     public function benchBruteForce(): void
     {
-        $searchedInterval = $this->generateInterval();
+        $searchedInterval = $this->generateInterval(self::MAX_INTERVAL_HIGH, self::MAX_INTERVAL_OFFSET);
         foreach ($this->bruteForceList as $interval) {
             if ($interval->intersect($searchedInterval)) {
                 break;
             }
         }
     }
-
-    /**
-     * @return NumericInterval
-     */
-    private function generateInterval(): NumericInterval
-    {
-        try {
-            $low = random_int(0, self::MAX_INTERVAL_HIGH);
-            $high = random_int($low, min($low + self::MAX_INTERVAL_OFFSET, self::MAX_INTERVAL_HIGH));
-        } catch (Exception $exception) {
-            echo 'Cannot generate interval: ' . $exception->getMessage();
-            exit;
-        }
-        return new NumericInterval($low, $high);
-    }
 }