diff --git a/modules/ml/misc/python/test/test_goodfeatures.py b/modules/ml/misc/python/test/test_goodfeatures.py
index a590ba9fa9..f41b615b50 100644
--- a/modules/ml/misc/python/test/test_goodfeatures.py
+++ b/modules/ml/misc/python/test/test_goodfeatures.py
@@ -17,7 +17,7 @@ class TestGoodFeaturesToTrack_test(NewOpenCVTests):
 
         results = dict([(t, cv.goodFeaturesToTrack(arr, numPoints, t, 2, useHarrisDetector=True)) for t in threshes])
         # Check that GoodFeaturesToTrack has not modified input image
-        self.assertTrue(arr.tostring() == original.tostring())
+        self.assertTrue(arr.tobytes() == original.tobytes())
         # Check for repeatability
         for i in range(1):
             results2 = dict([(t, cv.goodFeaturesToTrack(arr, numPoints, t, 2, useHarrisDetector=True)) for t in threshes])
diff --git a/modules/python/test/tests_common.py b/modules/python/test/tests_common.py
index c8b341d688..d6931829d3 100644
--- a/modules/python/test/tests_common.py
+++ b/modules/python/test/tests_common.py
@@ -58,7 +58,7 @@ class NewOpenCVTests(unittest.TestCase):
 
     def hashimg(self, im):
         """ Compute a hash for an image, useful for image comparisons """
-        return hashlib.md5(im.tostring()).hexdigest()
+        return hashlib.md5(im.tobytes()).hexdigest()
 
     if sys.version_info[:2] == (2, 6):
         def assertLess(self, a, b, msg=None):