diff --git a/Tests/test_file_tiff.py b/Tests/test_file_tiff.py
index 72156bb39..9c832c206 100644
--- a/Tests/test_file_tiff.py
+++ b/Tests/test_file_tiff.py
@@ -141,6 +141,137 @@ class TestFileTiff(PillowTestCase):
         self.assertEqual(
             im.getextrema(), (-3.140936851501465, 3.140684127807617))
 
+    def test___str__(self):
+        # Arrange
+        file = "Tests/images/pil136.tiff"
+        im = Image.open(file)
+
+        # Act
+        ret = str(im.ifd)
+
+        # Assert
+        self.assertIsInstance(ret, str)
+        self.assertEqual(
+            ret,
+            '{256: (55,), 257: (43,), 258: (8, 8, 8, 8), 259: (1,), '
+            '262: (2,), 296: (2,), 273: (8,), 338: (1,), 277: (4,), '
+            '279: (9460,), 282: ((720000, 10000),), '
+            '283: ((720000, 10000),), 284: (1,)}')
+
+    def test__delitem__(self):
+        # Arrange
+        file = "Tests/images/pil136.tiff"
+        im = Image.open(file)
+        len_before = len(im.ifd.as_dict())
+
+        # Act
+        del im.ifd[256]
+
+        # Assert
+        len_after = len(im.ifd.as_dict())
+        self.assertEqual(len_before, len_after + 1)
+
+    def test_load_byte(self):
+        # Arrange
+        from PIL import TiffImagePlugin
+        ifd = TiffImagePlugin.ImageFileDirectory()
+        data = b"abc"
+
+        # Act
+        ret = ifd.load_byte(data)
+
+        # Assert
+        self.assertEqual(ret, b"abc")
+
+    def test_load_string(self):
+        # Arrange
+        from PIL import TiffImagePlugin
+        ifd = TiffImagePlugin.ImageFileDirectory()
+        data = b"abc\0"
+
+        # Act
+        ret = ifd.load_string(data)
+
+        # Assert
+        self.assertEqual(ret, "abc")
+
+    def test_load_float(self):
+        # Arrange
+        from PIL import TiffImagePlugin
+        ifd = TiffImagePlugin.ImageFileDirectory()
+        data = b"abcdabcd"
+
+        # Act
+        ret = ifd.load_float(data)
+
+        # Assert
+        self.assertEqual(ret, (1.6777999408082104e+22, 1.6777999408082104e+22))
+
+    def test_load_double(self):
+        # Arrange
+        from PIL import TiffImagePlugin
+        ifd = TiffImagePlugin.ImageFileDirectory()
+        data = b"abcdefghabcdefgh"
+
+        # Act
+        ret = ifd.load_double(data)
+
+        # Assert
+        self.assertEqual(ret, (8.540883223036124e+194, 8.540883223036124e+194))
+
+    def test_seek(self):
+        # Arrange
+        file = "Tests/images/pil136.tiff"
+        im = Image.open(file)
+
+        # Act
+        im.seek(-1)
+
+        # Assert
+        self.assertEqual(im.tell(), 0)
+
+    def test_seek_eof(self):
+        # Arrange
+        file = "Tests/images/pil136.tiff"
+        im = Image.open(file)
+        self.assertEqual(im.tell(), 0)
+
+        # Act / Assert
+        self.assertRaises(EOFError, lambda: im.seek(1))
+
+    def test__cvt_res_int(self):
+        # Arrange
+        from PIL.TiffImagePlugin import _cvt_res
+        value = 34
+
+        # Act
+        ret = _cvt_res(value)
+
+        # Assert
+        self.assertEqual(ret, (34, 1))
+
+    def test__cvt_res_float(self):
+        # Arrange
+        from PIL.TiffImagePlugin import _cvt_res
+        value = 22.3
+
+        # Act
+        ret = _cvt_res(value)
+
+        # Assert
+        self.assertEqual(ret, (1461452, 65536))
+
+    def test__cvt_res_sequence(self):
+        # Arrange
+        from PIL.TiffImagePlugin import _cvt_res
+        value = [0, 1]
+
+        # Act
+        ret = _cvt_res(value)
+
+        # Assert
+        self.assertEqual(ret, [0, 1])
+
 
 if __name__ == '__main__':
     unittest.main()