diff --git a/.github/workflows/php.yml b/.github/workflows/php.yml
index 121b41b..e03a4c9 100644
--- a/.github/workflows/php.yml
+++ b/.github/workflows/php.yml
@@ -105,11 +105,11 @@ jobs:
         if: steps.phpunit.outcome == 'success'
         run: composer test:infection
 
-#       # This step runs static analysis with PHPStan.
-#       - name: Run static analysis with PHPStan
-#         id: phpstan
-#         if: steps.infection.outcome == 'success'
-#         run: composer test:phpstan
+      # This step runs static analysis with PHPStan.
+      - name: Run static analysis with PHPStan
+        id: phpstan
+        if: steps.infection.outcome == 'success'
+        run: composer test:phpstan
 #
 #       # This step runs static analysis with Phan.
 #       - name: Run static analysis with phan
diff --git a/composer.json b/composer.json
index 029ce25..cd38c58 100644
--- a/composer.json
+++ b/composer.json
@@ -52,6 +52,8 @@
     "php-parallel-lint/php-console-highlighter": "^1",
     "php-parallel-lint/php-parallel-lint": "^1",
     "phpmd/phpmd": "^2",
+    "phpstan/phpstan": "^1.10",
+    "phpstan/phpstan-phpunit": "^1.3",
     "phpunit/php-code-coverage": "^10|^11",
     "phpunit/phpunit": "^10|^11"
   },
@@ -66,12 +68,14 @@
       "@test:lint",
       "@test:code-style",
       "@test:phpmd",
-      "@test:infection"
+      "@test:infection",
+      "@test:phpstan"
     ],
     "test:code-style": "pint --test",
     "test:infection": "infection --min-msi=100 --min-covered-msi=100 --threads=4 --show-mutations --only-covered --formatter=progress",
     "test:lint": "parallel-lint --exclude vendor --show-deprecated .",
     "test:phpmd": "phpmd src,tests text phpmd.xml",
+    "test:phpstan": "php -d memory_limit=-1 ./vendor/bin/phpstan analyse --no-progress --no-interaction",
     "test:phpunit": "phpunit --no-coverage --no-logging",
     "test:vulnerabilities-check": "php -d memory_limit=-1 ./vendor/bin/security-checker security:check"
   },
@@ -80,6 +84,7 @@
     "test:infection": "Conduct mutation testing for robustness.",
     "test:lint": "Search for syntax errors and problematic patterns.",
     "test:phpmd": "Detect bugs and suboptimal code with PHP Mess Detector.",
+    "test:phpstan": "Conduct PHPStan static analysis for identifying code quality issues.",
     "test:phpunit": "Execute PHPUnit tests to verify code functionality.",
     "test:vulnerabilities-check": "Scan dependencies for known security vulnerabilities."
   }
diff --git a/localTest.sh b/localTest.sh
index f6c0236..accb69e 100755
--- a/localTest.sh
+++ b/localTest.sh
@@ -23,7 +23,8 @@ for version in {81..83}; do
     rm -f composer.lock && \
     $DOCKER_CMD composer install && \
     $DOCKER_CMD composer update --with-all-dependencies && \
-    $DOCKER_CMD composer require --dev --with-all-dependencies rector/rector
+    $DOCKER_CMD composer require --dev --with-all-dependencies "phpstan/phpstan":"^1.10"  && \
+    $DOCKER_CMD composer require --dev --with-all-dependencies "phpstan/phpstan-phpunit":"^1.3"
 
     # Check for errors immediately after Composer commands
     if [ $? -ne 0 ]; then
diff --git a/phpstan.neon b/phpstan.neon
new file mode 100644
index 0000000..151ec49
--- /dev/null
+++ b/phpstan.neon
@@ -0,0 +1,12 @@
+parameters:
+    level: max
+    phpVersion: 80100
+    checkMissingIterableValueType: true
+    checkGenericClassInNonGenericObjectType: true
+    treatPhpDocTypesAsCertain: false
+    tipsOfTheDay: false
+    reportWrongPhpDocTypeInVarTag: true
+    paths:
+        - src
+        - tests
+    ignoreErrors:
\ No newline at end of file
diff --git a/src/Trace.php b/src/Trace.php
index bbd5d67..75c56e3 100644
--- a/src/Trace.php
+++ b/src/Trace.php
@@ -288,8 +288,6 @@ private static function computeCombinedRankings(array $filteredData): array
      * @param array<int, array{ct: int, wt: int, cpu: int, mu: int, pmu: int, name: string}> $data
      *
      * @return array<string, int> An associative array where keys are function names and values are their ranks.
-     *
-     * @psalm-return array<string, int<1, max>>
      */
     private static function rankByMetric(array $data, string $metric): array
     {
@@ -319,20 +317,38 @@ private static function rankByMetric(array $data, string $metric): array
     }
 
 
+    /**
+     * Calculates the rank for a given metric.
+     *
+     * @param array{ct: int, wt: int, cpu: int, mu: int, pmu: int, name: string} $item The array containing the metrics
+     *     and name for which the rank is calculated.
+     *
+     * @return array{int, int, int|string}
+     */
     private static function calculateRank(
         array $item,
         string $metric,
         int $currentRank,
         int $sameMetricValueCount,
-        $previousMetricValue
+        null|int|string $previousMetricValue
     ): array {
         if ($previousMetricValue === null || $item[$metric] === $previousMetricValue) {
-            $sameMetricValueCount++;
-            return [$currentRank, $sameMetricValueCount, $item[$metric]];
+            ++$sameMetricValueCount;
+
+            return [
+                $currentRank,
+                $sameMetricValueCount,
+                $item[$metric],
+            ];
         }
 
         $currentRank += $sameMetricValueCount;
         $sameMetricValueCount = 1;
-        return [$currentRank, $sameMetricValueCount, $item[$metric]];
+
+        return [
+            $currentRank,
+            $sameMetricValueCount,
+            $item[$metric],
+        ];
     }
 }