diff --git a/chapter11/animals_ann.py b/chapter11/animals_ann.py
index 917bdd4..90c9dec 100755
--- a/chapter11/animals_ann.py
+++ b/chapter11/animals_ann.py
@@ -24,7 +24,7 @@ def dog_class():
     return [1, 0, 0, 0]
 
 def condor_sample():
-    return [uniform(3.0, 10.0), randint(3.0, 5.0), 0]
+    return [uniform(3.0, 10.0), randint(3, 5), 0]
 
 def condor_class():
     return [0, 1, 0, 0]
diff --git a/chapter11/hand-gesture-recognition/detect_gesture.py b/chapter11/hand-gesture-recognition/detect_gesture.py
index f7e0973..e6d42bd 100644
--- a/chapter11/hand-gesture-recognition/detect_gesture.py
+++ b/chapter11/hand-gesture-recognition/detect_gesture.py
@@ -56,7 +56,7 @@
         # Flip the image horizontally for a selfie-view display.
         final = cv2.flip(image, 1)
         cv2.putText(final, gestures[gesture_index],
-                    (10, 30), cv2.FONT_HERSHEY_DUPLEX, 1, 255)
+                    (10, 30), cv2.FONT_HERSHEY_DUPLEX, 1, (255, 255, 255))
         cv2.imshow('MediaPipe Hands', final)
         if cv2.waitKey(5) & 0xFF == 27:
             break
diff --git a/chapter11/hand-gesture-recognition/landmark_utils/utils.py b/chapter11/hand-gesture-recognition/landmark_utils/utils.py
index ccc8d20..2a49aab 100644
--- a/chapter11/hand-gesture-recognition/landmark_utils/utils.py
+++ b/chapter11/hand-gesture-recognition/landmark_utils/utils.py
@@ -25,8 +25,8 @@ def calc_bounding_rect(image, landmarks):
 
 def log_csv(number, landmark_list):
     if number > 9 or number == -1:
-        pass
-    csv_path = csv_path = 'model/keypoint_classifier/keypoint.csv'
+        return
+    csv_path = 'model/keypoint_classifier/keypoint.csv'
     with open(csv_path, 'a', newline="") as f:
         writer = csv.writer(f)
         writer.writerow([number, *landmark_list])
diff --git a/chapter11/hand-gesture-recognition/train.py b/chapter11/hand-gesture-recognition/train.py
index 333a621..62d49f8 100644
--- a/chapter11/hand-gesture-recognition/train.py
+++ b/chapter11/hand-gesture-recognition/train.py
@@ -25,7 +25,7 @@ def main():
                 # If loading a video, use 'break' instead of 'continue'.
                 continue
             receivedKey = cv2.waitKey(20)
-            number = receivedKey - 48
+            number = (receivedKey - 48) if receivedKey != -1 else -1
             # To improve performance, optionally mark the image as not writeable to
             # pass by reference.
             image.flags.writeable = False
diff --git a/chapter12/tests/unit/test_handler.py b/chapter12/tests/unit/test_handler.py
index ab6d6a0..b11a047 100644
--- a/chapter12/tests/unit/test_handler.py
+++ b/chapter12/tests/unit/test_handler.py
@@ -1,5 +1,6 @@
 import json
 
+import numpy as np
 import pytest
 
 from hello_world import app
@@ -34,7 +35,7 @@ def apigw_event():
             },
             "stage": "prod",
         },
-        "queryStringParameters": {"foo": "bar"},
+        "queryStringParameters": {"url": "https://example.com/test.jpg"},
         "headers": {
             "Via": "1.1 08f323deadbeefa7af34d5feb414ce27.cloudfront.net (CloudFront)",
             "Accept-Language": "en-US,en;q=0.8",
@@ -63,10 +64,13 @@ def apigw_event():
 
 
 def test_lambda_handler(apigw_event, mocker):
+    mock_response = mocker.MagicMock()
+    mock_response.content = b""
+    mocker.patch("hello_world.app.requests.get", return_value=mock_response)
+    mocker.patch("hello_world.app.cv2.imread", return_value=np.zeros((100, 100, 3), dtype=np.uint8))
 
     ret = app.lambda_handler(apigw_event, "")
     data = json.loads(ret["body"])
 
     assert ret["statusCode"] == 200
-    assert "message" in ret["body"]
-    assert data["message"] == "hello world"
+    assert "coords" in data