diff --git a/PIL/TiffImagePlugin.py b/PIL/TiffImagePlugin.py
index 524d42a34..7e073b49d 100644
--- a/PIL/TiffImagePlugin.py
+++ b/PIL/TiffImagePlugin.py
@@ -1359,7 +1359,7 @@ def _save(im, fp, filename):
                     IPTC_NAA_CHUNK, PHOTOSHOP_CHUNK, XMP):
             if key in im.tag_v2:
                 ifd[key] = im.tag_v2[key]
-            ifd.tagtype[key] = im.tag_v2.tagtype.get(key, None)
+                ifd.tagtype[key] = im.tag_v2.tagtype[key]
 
         # preserve ICC profile (should also work when saving other formats
         # which support profiles as TIFF) -- 2008-06-06 Florian Hoech
diff --git a/Tests/test_file_tiff.py b/Tests/test_file_tiff.py
index 9858ce5a0..9a2ce27d8 100644
--- a/Tests/test_file_tiff.py
+++ b/Tests/test_file_tiff.py
@@ -1,5 +1,6 @@
 from __future__ import print_function
 import logging
+from io import BytesIO
 import struct
 
 from helper import unittest, PillowTestCase, hopper, py3
@@ -103,6 +104,15 @@ class TestFileTiff(PillowTestCase):
         im._setup()
         self.assertEqual(im.info['dpi'], (71., 71.))
 
+    def test_save_setting_missing_resolution(self):
+        from PIL.TiffImagePlugin import X_RESOLUTION, Y_RESOLUTION
+        b = BytesIO()
+        Image.open("Tests/images/10ct_32bit_128.tiff").save(
+            b, format="tiff", resolution=123.45)
+        im = Image.open(b)
+        self.assertEqual(float(im.tag_v2[X_RESOLUTION]), 123.45)
+        self.assertEqual(float(im.tag_v2[Y_RESOLUTION]), 123.45)
+
     def test_invalid_file(self):
         invalid_file = "Tests/images/flower.jpg"