diff --git a/komrade/backend/crypt.py b/komrade/backend/crypt.py
index 8be947c..eef5f53 100644
--- a/komrade/backend/crypt.py
+++ b/komrade/backend/crypt.py
@@ -35,6 +35,7 @@ class Crypt(Logger):
         # return zlib.adler32(binary_data)
 
     def force_binary(self,k_b):
+        if k_b is None: return b''
         if type(k_b)==str: k_b=k_b.encode()
         if type(k_b)!=bytes: k_b=k_b.decode()
         return k_b