diff --git a/test/codec_doctest.py b/test/codec_doctest.py
new file mode 100644
index 0000000..ec2f8bc
--- /dev/null
+++ b/test/codec_doctest.py
@@ -0,0 +1,19 @@
+"""
+>>> import pEp
+>>> def messageToSend(msg):
+...   m, keys, rating, flags = msg.decrypt()
+...   try:
+...     m.attachments[0].decode()
+...     print("decode successfull")
+...   except UnicodeDecodeError as e:
+...     print("decode failed")
+>>> pEp.messageToSend = messageToSend
+>>> pEp.key_reset_all_own_keys()
+decode successfull
+decode successfull
+decode successfull
+"""
+
+if __name__ == "__main__":
+    import doctest
+    doctest.testmod()