diff --git a/mediapipe/tasks/web/vision/pose_landmarker/pose_landmarker.ts b/mediapipe/tasks/web/vision/pose_landmarker/pose_landmarker.ts
index 44effa879..2d72bf1dc 100644
--- a/mediapipe/tasks/web/vision/pose_landmarker/pose_landmarker.ts
+++ b/mediapipe/tasks/web/vision/pose_landmarker/pose_landmarker.ts
@@ -62,12 +62,9 @@ export type PoseLandmarkerCallback = (result: PoseLandmarkerResult) => void;
 
 /** Performs pose landmarks detection on images. */
 export class PoseLandmarker extends VisionTaskRunner {
-  private result: PoseLandmarkerResult = {
-    landmarks: [],
-    worldLandmarks: [],
-    auxilaryLandmarks: []
-  };
+  private result: Partial<PoseLandmarkerResult> = {};
   private outputSegmentationMasks = false;
+  private userCallback: PoseLandmarkerCallback = () => {};
   private readonly options: PoseLandmarkerGraphOptions;
   private readonly poseLandmarksDetectorGraphOptions:
       PoseLandmarksDetectorGraphOptions;
@@ -239,14 +236,13 @@ export class PoseLandmarker extends VisionTaskRunner {
         typeof imageProcessingOptionsOrCallback !== 'function' ?
         imageProcessingOptionsOrCallback :
         {};
-    const userCallback =
-        typeof imageProcessingOptionsOrCallback === 'function' ?
+    this.userCallback = typeof imageProcessingOptionsOrCallback === 'function' ?
         imageProcessingOptionsOrCallback :
         callback!;
 
     this.resetResults();
     this.processImageData(image, imageProcessingOptions);
-    userCallback(this.result);
+    this.userCallback = () => {};
   }
 
   /**
@@ -293,19 +289,33 @@ export class PoseLandmarker extends VisionTaskRunner {
     const timestamp = typeof timestampOrImageProcessingOptions === 'number' ?
         timestampOrImageProcessingOptions :
         timestampOrCallback as number;
-    const userCallback = typeof timestampOrCallback === 'function' ?
+    this.userCallback = typeof timestampOrCallback === 'function' ?
         timestampOrCallback :
         callback!;
     this.resetResults();
     this.processVideoData(videoFrame, imageProcessingOptions, timestamp);
-    userCallback(this.result);
+    this.userCallback = () => {};
   }
 
   private resetResults(): void {
-    this.result = {landmarks: [], worldLandmarks: [], auxilaryLandmarks: []};
-    if (this.outputSegmentationMasks) {
-      this.result.segmentationMasks = [];
+    this.result = {};
+  }
+
+  /** Invokes the user callback once all data has been received. */
+  private maybeInvokeCallback(): void {
+    if (!('landmarks' in this.result)) {
+      return;
     }
+    if (!('worldLandmarks' in this.result)) {
+      return;
+    }
+    if (!('landmarks' in this.result)) {
+      return;
+    }
+    if (this.outputSegmentationMasks && !('segmentationMasks' in this.result)) {
+      return;
+    }
+    this.userCallback(this.result as Required<PoseLandmarkerResult>);
   }
 
   /** Sets the default values for the graph. */
@@ -385,30 +395,39 @@ export class PoseLandmarker extends VisionTaskRunner {
         NORM_LANDMARKS_STREAM, (binaryProto, timestamp) => {
           this.addJsLandmarks(binaryProto);
           this.setLatestOutputTimestamp(timestamp);
+          this.maybeInvokeCallback();
         });
     this.graphRunner.attachEmptyPacketListener(
         NORM_LANDMARKS_STREAM, timestamp => {
+          this.result.landmarks = [];
           this.setLatestOutputTimestamp(timestamp);
+          this.maybeInvokeCallback();
         });
 
     this.graphRunner.attachProtoVectorListener(
         WORLD_LANDMARKS_STREAM, (binaryProto, timestamp) => {
           this.adddJsWorldLandmarks(binaryProto);
           this.setLatestOutputTimestamp(timestamp);
+          this.maybeInvokeCallback();
         });
     this.graphRunner.attachEmptyPacketListener(
         WORLD_LANDMARKS_STREAM, timestamp => {
+          this.result.worldLandmarks = [];
           this.setLatestOutputTimestamp(timestamp);
+          this.maybeInvokeCallback();
         });
 
     this.graphRunner.attachProtoVectorListener(
         AUXILIARY_LANDMARKS_STREAM, (binaryProto, timestamp) => {
           this.addJsAuxiliaryLandmarks(binaryProto);
           this.setLatestOutputTimestamp(timestamp);
+          this.maybeInvokeCallback();
         });
     this.graphRunner.attachEmptyPacketListener(
         AUXILIARY_LANDMARKS_STREAM, timestamp => {
+          this.result.auxilaryLandmarks = [];
           this.setLatestOutputTimestamp(timestamp);
+          this.maybeInvokeCallback();
         });
 
     if (this.outputSegmentationMasks) {
@@ -419,10 +438,13 @@ export class PoseLandmarker extends VisionTaskRunner {
             this.result.segmentationMasks =
                 masks.map(wasmImage => this.convertToMPImage(wasmImage));
             this.setLatestOutputTimestamp(timestamp);
+            this.maybeInvokeCallback();
           });
       this.graphRunner.attachEmptyPacketListener(
           SEGMENTATION_MASK_STREAM, timestamp => {
+            this.result.segmentationMasks = [];
             this.setLatestOutputTimestamp(timestamp);
+            this.maybeInvokeCallback();
           });
     }
 
diff --git a/mediapipe/tasks/web/vision/pose_landmarker/pose_landmarker_test.ts b/mediapipe/tasks/web/vision/pose_landmarker/pose_landmarker_test.ts
index 2d76f656f..794df68b8 100644
--- a/mediapipe/tasks/web/vision/pose_landmarker/pose_landmarker_test.ts
+++ b/mediapipe/tasks/web/vision/pose_landmarker/pose_landmarker_test.ts
@@ -260,4 +260,38 @@ describe('PoseLandmarker', () => {
     expect(landmarks1).toBeDefined();
     expect(landmarks1).toEqual(landmarks2);
   });
+
+  it('invokes listener once masks are avaiblae', (done) => {
+    const landmarksProto = [createLandmarks().serializeBinary()];
+    const worldLandmarksProto = [createWorldLandmarks().serializeBinary()];
+    const masks = [
+      {data: new Float32Array([0, 1, 2, 3]), width: 2, height: 2},
+    ];
+    let listenerCalled = false;
+
+
+    poseLandmarker.setOptions({outputSegmentationMasks: true});
+
+    // Pass the test data to our listener
+    poseLandmarker.fakeWasmModule._waitUntilIdle.and.callFake(() => {
+      expect(listenerCalled).toBeFalse();
+      poseLandmarker.listeners.get('normalized_landmarks')!
+          (landmarksProto, 1337);
+      expect(listenerCalled).toBeFalse();
+      poseLandmarker.listeners.get('world_landmarks')!
+          (worldLandmarksProto, 1337);
+      expect(listenerCalled).toBeFalse();
+      poseLandmarker.listeners.get('auxiliary_landmarks')!
+          (landmarksProto, 1337);
+      expect(listenerCalled).toBeFalse();
+      poseLandmarker.listeners.get('segmentation_masks')!(masks, 1337);
+      expect(listenerCalled).toBeTrue();
+      done();
+    });
+
+    // Invoke the pose landmarker
+    poseLandmarker.detect({} as HTMLImageElement, () => {
+      listenerCalled = true;
+    });
+  });
 });