#3694: add test for fix committed in r66693.
diff --git a/Lib/test/test_struct.py b/Lib/test/test_struct.py
index a4dc9ca..6e35db8 100644
--- a/Lib/test/test_struct.py
+++ b/Lib/test/test_struct.py
@@ -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)