diff --git a/src/driver/ChangeObserver/DatabaseChangeObserver.ts b/src/driver/ChangeObserver/DatabaseChangeObserver.ts
index db20e3c..cfeaaf0 100644
--- a/src/driver/ChangeObserver/DatabaseChangeObserver.ts
+++ b/src/driver/ChangeObserver/DatabaseChangeObserver.ts
@@ -70,7 +70,7 @@ export abstract class DatabaseChangeObserver<T>
         const duration = performance.now() - start
         return {
             path,
-            durationMillis: Math.abs(duration),
+            durationMillis: duration,
         }
     }
 
diff --git a/src/driver/PubSub/InProcessFirebasePubSub.ts b/src/driver/PubSub/InProcessFirebasePubSub.ts
index e22a486..8c4b6fe 100644
--- a/src/driver/PubSub/InProcessFirebasePubSub.ts
+++ b/src/driver/PubSub/InProcessFirebasePubSub.ts
@@ -95,7 +95,7 @@ export class InProcessFirebaseBuilderPubSub implements IFirebaseBuilderPubSub {
                     }).then(() =>
                         resolve({
                             topicName,
-                            durationMillis: start - performance.now(),
+                            durationMillis: performance.now() - start,
                         }),
                     )
                 },
diff --git a/src/driver/RealtimeDatabase/InProcessRealtimeDatabase.ts b/src/driver/RealtimeDatabase/InProcessRealtimeDatabase.ts
index 6d195f3..3e6097d 100644
--- a/src/driver/RealtimeDatabase/InProcessRealtimeDatabase.ts
+++ b/src/driver/RealtimeDatabase/InProcessRealtimeDatabase.ts
@@ -545,7 +545,7 @@ export class InProcessRealtimeDatabase implements IFirebaseRealtimeDatabase {
                     observer.onChange({ before, after, data, delta }).then(() =>
                         resolve({
                             path,
-                            durationMillis: start - performance.now(),
+                            durationMillis: performance.now() - start,
                         }),
                     )
                 },