diff --git a/pynetstring.py b/pynetstring.py
index <HASH>..<HASH> 100644
--- a/pynetstring.py
+++ b/pynetstring.py
@@ -9,7 +9,7 @@ EMPTY = b''
 def _encode(data):
     if isinstance(data, str):
         data = bytes(data, 'utf-8')
-    return b'%d:%s' % (len(data), data)
+    return b'%d:%s,' % (len(data), data)
 
 def encode(data):
     if isinstance(data, list):
Add comma that went missing in d<I>f<I>aa<I>b<I>bff<I>ccd<I>c5f<I>fa<I>