diff --git a/modules/prometheusio_exporter_database/src/EventSubscriber/DatabaseCollector.php b/modules/prometheusio_exporter_database/src/EventSubscriber/DatabaseCollector.php
index 8a57ea2..63ca09b 100644
--- a/modules/prometheusio_exporter_database/src/EventSubscriber/DatabaseCollector.php
+++ b/modules/prometheusio_exporter_database/src/EventSubscriber/DatabaseCollector.php
@@ -118,16 +118,16 @@ class DatabaseCollector implements EventSubscriberInterface, BaseMetricsSourceIn
    *   The total time of the select queries.
    */
   protected function getTotalTimeInMs(array $queries) {
-    $totalTimeInMs = 0;
+    $totalTimeInUs = 0;
     foreach ($queries as $query) {
       // Consider only SELECTs.
       if (strpos($query['query'], 'SELECT') === FALSE) {
         continue;
       }
-      // Queries have microsecond precision.
-      $totalTimeInMs = $query['time'] * 1000;
+      $totalTimeInUs += $query['time'];
     }
-    return $totalTimeInMs;
+    // Queries have microsecond precision.
+    return $totalTimeInUs * 1000;
   }
 
 }