diff --git a/shotgun_api3/lib/mimetypes.py b/shotgun_api3/lib/mimetypes.py
index 8416aa630..236c33312 100644
--- a/shotgun_api3/lib/mimetypes.py
+++ b/shotgun_api3/lib/mimetypes.py
@@ -112,7 +112,12 @@ def guess_type(self, url, strict=True):
         Optional `strict' argument when False adds a bunch of commonly found,
         but non-standard types.
         """
-        scheme, url = urllib.parse.splittype(url)
+        # urllib.splittype is no longer exposed in Python 3.  To replicate its functionality, we'll
+        # use urlparse.urlsplit to find the scheme, and then truncate the head of the url to omit
+        # the scheme plus the following colon.  This replicates the functionality of urllib.splittype.
+        scheme = urllib.parse.urlsplit(url)[0]
+        url = url[(len(scheme) + 1):]
+
         if scheme == 'data':
             # syntax of data URLs:
             # dataurl   := "data:" [ mediatype ] [ ";base64" ] "," data
diff --git a/tests/tests_unit.py b/tests/tests_unit.py
index 01555d188..d3c059c29 100644
--- a/tests/tests_unit.py
+++ b/tests/tests_unit.py
@@ -430,6 +430,17 @@ def test_correct_mimetypes_imported(self):
         self._test_mimetypes_import("win32", 3, 0, 0, False)
         self._test_mimetypes_import("darwin", 2, 7, 0, False)
 
+    def test_patched_mimetypes(self):
+        """
+        Test patched mimetypes `guess_type` method to ensure it works as expected.
+        """
+        from shotgun_api3.lib import mimetypes as mimetypes_patched
+        self.assertEqual(mimetypes_patched.guess_type("foo.html"), ("text/html", None))
+        self.assertEqual(mimetypes_patched.guess_type("foo.tgz"), ("application/x-tar", "gzip"))
+        self.assertEqual(mimetypes_patched.guess_type("foo.tar.gz"), ("application/x-tar", "gzip"))
+        self.assertEqual(mimetypes_patched.guess_type("foo.tar.Z"), ("application/x-tar", "compress"))
+        self.assertEqual(mimetypes_patched.guess_type("foo.tar.bz2"), ("application/x-tar", "bzip2"))
+        self.assertEqual(mimetypes_patched.guess_type("foo.tar.xz"), ("application/x-tar", "xz"))
 
 if __name__ == '__main__':
     unittest.main()