Index: Lib/test/test_struct.py
===================================================================
--- Lib/test/test_struct.py	(revision 69418)
+++ Lib/test/test_struct.py	(working copy)
@@ -512,6 +512,10 @@
         self.assertRaises(struct.error, s.pack_into, small_buf, 0, test_string)
         self.assertRaises(struct.error, s.pack_into, small_buf, 2, test_string)
 
+        # Test bogus offset (issue 3694)
+        sb = small_buf
+        self.assertRaises(TypeError, struct.pack_into, b'1', sb, None)
+
     def test_pack_into_fn(self):
         test_string = 'Reykjavik rocks, eow!'
         writable_buf = array.array('c', ' '*100)