diff --git a/.github/workflows/tests.yml b/.github/workflows/tests.yml
index fb53ece87..ebd699f6f 100644
--- a/.github/workflows/tests.yml
+++ b/.github/workflows/tests.yml
@@ -103,6 +103,14 @@ jobs:
       - name: Checkout
         uses: actions/checkout@v4
 
+      - name: Setup PHP
+        uses: shivammathur/setup-php@v2
+        with:
+          php-version: "8.2"
+
+      - name: Install PHP Dependencies
+        run: composer install --no-dev --no-interaction --prefer-dist --optimize-autoloader
+
       - name: Run WP Performance Tests
         uses: swissspidy/wp-performance-action@v2
         with:
@@ -113,3 +121,4 @@ jobs:
           create-comment: ${{ github.event_name == 'pull_request' }}
           print-results: true
           upload-artifacts: true
+          debug: ${{ runner.debug == '1' }}
diff --git a/tests/performance-comparator.php b/tests/performance-comparator.php
index c731e4354..deae90dd9 100755
--- a/tests/performance-comparator.php
+++ b/tests/performance-comparator.php
@@ -22,6 +22,18 @@ class Performance_Comparator {
         'memory_usage_mb' => 40,   // 40% increase for critical
         'database_queries' => 25,  // 25% increase for critical
     ];
+
+    /**
+     * Minimum absolute change required before a percentage threshold is applied.
+     * Prevents false positives on sub-millisecond measurements where CI runner
+     * noise (scheduler jitter, CPU load) dominates over real regressions.
+     * A 42% change on 0.26ms is only 0.11ms — well within normal system noise.
+     */
+    private $minimum_absolute_change = [
+        'execution_time_ms' => 1.0, // Ignore changes smaller than 1ms
+        'memory_usage_mb' => 0.5,   // Ignore changes smaller than 0.5MB
+        'database_queries' => 1,    // Ignore changes smaller than 1 query
+    ];
     
     public function __construct($baseline_file, $current_file) {
         $this->baseline_results = $this->load_results($baseline_file);
@@ -118,13 +130,24 @@ private function compare_benchmark($benchmark) {
             
             $change_percent = (($current_value - $baseline_value) / $baseline_value) * 100;
             
+            $absolute_change = $current_value - $baseline_value;
+
             $result['changes'][$metric] = [
                 'baseline' => $baseline_value,
                 'current' => $current_value,
                 'change_percent' => round($change_percent, 2),
-                'change_absolute' => $current_value - $baseline_value
+                'change_absolute' => $absolute_change
             ];
-            
+
+            // Skip threshold checks when the absolute change is below the noise floor.
+            // Sub-millisecond timing differences are dominated by CI runner jitter and
+            // do not represent real regressions.
+            $min_absolute = $this->minimum_absolute_change[$metric] ?? 0;
+            if (abs($absolute_change) < $min_absolute) {
+                // Treat as no_change — noise floor not exceeded
+                continue;
+            }
+
             // Check for critical regression
             if ($change_percent > $this->critical_thresholds[$metric]) {
                 $result['status'] = 'critical_regression';