diff --git a/pysrt/srttime.py b/pysrt/srttime.py
index 0481b68..a94087b 100644
--- a/pysrt/srttime.py
+++ b/pysrt/srttime.py
@@ -93,6 +93,19 @@ def __imul__(self, ratio):
         self.ordinal = int(round(self.ordinal * ratio))
         return self
 
+    def __div__(self, ratio):
+        return self.from_ordinal(int(round(self.ordinal / ratio)))
+
+    def __idiv__(self, ratio):
+        self.ordinal = int(round(self.ordinal / ratio))
+        return self
+
+    def __truediv__(self, ratio):
+        return self.__div__(ratio)
+
+    def __itruediv__(self, ratio):
+        return self.__idiv__(ratio)
+
     @classmethod
     def coerce(cls, other):
         """
@@ -130,7 +143,7 @@ def shift(self, *args, **kwargs):
         All arguments are optional and have a default value of 0.
         """
         if 'ratio' in kwargs:
-            self *= kwargs.pop('ratio')
+            self /= kwargs.pop('ratio')
         self += self.__class__(*args, **kwargs)
 
     @classmethod
diff --git a/tests/test_srtfile.py b/tests/test_srtfile.py
index aceb18e..aede21b 100644
--- a/tests/test_srtfile.py
+++ b/tests/test_srtfile.py
@@ -128,7 +128,7 @@ def test_shift(self):
         srt_file.shift(1, 1, 1, 1)
         self.assertEqual(srt_file[0].end, (1, 1, 1, 1))
         srt_file.shift(ratio=2)
-        self.assertEqual(srt_file[0].end, (2, 2, 2, 2))
+        self.assertEqual(srt_file[0].end, (0, 30, 30, 500))
 
 
 class TestText(unittest.TestCase):
diff --git a/tests/test_srtitem.py b/tests/test_srtitem.py
index f4a6f2f..d09bec8 100644
--- a/tests/test_srtitem.py
+++ b/tests/test_srtitem.py
@@ -81,7 +81,7 @@ def setUp(self):
     def test_italics_tag(self):
         self.item.text = "<i>Hello world !</i>"
         self.assertEqual(self.item.text_without_tags,'Hello world !')
-        
+
     def test_bold_tag(self):
         self.item.text = "<b>Hello world !</b>"
         self.assertEqual(self.item.text_without_tags,'Hello world !')
@@ -126,10 +126,10 @@ def test_shift_down(self):
 
     def test_shift_by_ratio(self):
         self.item.shift(ratio=2)
-        self.assertEqual(self.item.start, {'minutes': 2})
-        self.assertEqual(self.item.end, {'minutes': 2, 'seconds': 40})
-        self.assertEqual(self.item.duration, (0, 0, 40, 0))
-        self.assertEqual(self.item.characters_per_second, 0.325)
+        self.assertEqual(self.item.start, {'seconds': 30})
+        self.assertEqual(self.item.end, {'seconds': 40})
+        self.assertEqual(self.item.duration, (0, 0, 10, 0))
+        self.assertEqual(self.item.characters_per_second, 1.3)
 
 
 class TestOperators(unittest.TestCase):
diff --git a/tests/test_srttime.py b/tests/test_srttime.py
index 1eb6804..dfd4c6a 100644
--- a/tests/test_srttime.py
+++ b/tests/test_srttime.py
@@ -146,5 +146,15 @@ def test_imul(self):
         self.time *= 0.5
         self.assertEqual(self.time, (1, 2, 3, 4))
 
+    def test_div(self):
+        self.assertEqual(self.time / 0.5, SubRipTime(2, 4, 6, 8))
+        self.assertEqual(self.time / 2, (0, 31, 1, 502))
+
+    def test_idiv(self):
+        self.time /= 0.5
+        self.assertEqual(self.time, (2, 4, 6, 8))
+        self.time /= 2
+        self.assertEqual(self.time, (1, 2, 3, 4))
+
 if __name__ == '__main__':
     unittest.main()