diff --git a/parsely/src/main/java/com/parsely/parselyandroid/ParselyTracker.java b/parsely/src/main/java/com/parsely/parselyandroid/ParselyTracker.java
index 1c683f18..77ff8053 100644
--- a/parsely/src/main/java/com/parsely/parselyandroid/ParselyTracker.java
+++ b/parsely/src/main/java/com/parsely/parselyandroid/ParselyTracker.java
@@ -351,15 +351,15 @@ public void trackPlay(
                 videoEngagementManager = null;
             }
         }
-        final @NonNull String uuid = generatePixelId();
+        @NonNull final String uuid = generatePixelId();
 
         // Enqueue the videostart
-        Map<String, Object> videostartEvent = buildEvent(url, urlRef, "videostart", videoMetadata, extraData);
+        @NonNull final Map<String, Object> videostartEvent = buildEvent(url, urlRef, "videostart", videoMetadata, extraData);
         videostartEvent.put(VIDEO_START_ID_KEY, uuid);
         enqueueEvent(videostartEvent);
 
         // Start a new engagement manager for the video.
-        Map<String, Object> hbEvent = buildEvent(url, urlRef, "vheartbeat", videoMetadata, extraData);
+        @NonNull final Map<String, Object> hbEvent = buildEvent(url, urlRef, "vheartbeat", videoMetadata, extraData);
         hbEvent.put(VIDEO_START_ID_KEY, uuid);
         // TODO: Can we remove some metadata fields from this request?
         videoEngagementManager = new EngagementManager(timer, DEFAULT_ENGAGEMENT_INTERVAL_MILLIS, hbEvent);
@@ -412,6 +412,7 @@ public void resetVideo() {
      * @param extraData A Map of additional information to send with the event.
      * @return A Map object representing the event to be sent to Parse.ly.
      */
+    @NonNull
     private Map<String, Object> buildEvent(
             String url,
             String urlRef,