diff --git a/mtcnn/mtcnn.py b/mtcnn/mtcnn.py
index 3db8b8c..9cd7bf9 100644
--- a/mtcnn/mtcnn.py
+++ b/mtcnn/mtcnn.py
@@ -36,7 +36,6 @@
 from mtcnn.exceptions import InvalidImage
 from mtcnn.network.factory import NetworkFactory
 
-
 __author__ = "Iván de Paz Centeno"
 
 
@@ -87,7 +86,6 @@ def __init__(self, weights_file: str = None, min_face_size: int = 20, steps_thre
 
         self._pnet, self._rnet, self._onet = NetworkFactory().build_P_R_O_nets_from_file(weights_file)
 
-
     @property
     def min_face_size(self):
         return self._min_face_size
@@ -307,7 +305,7 @@ def detect_faces(self, img) -> list:
 
         for bounding_box, keypoints in zip(total_boxes, points.T):
             bounding_boxes.append({
-                'box': [int(bounding_box[0]), int(bounding_box[1]),
+                'box': [max(0, int(bounding_box[0])), max(0, int(bounding_box[1])),
                         int(bounding_box[2] - bounding_box[0]), int(bounding_box[3] - bounding_box[1])],
                 'confidence': bounding_box[-1],
                 'keypoints': {