diff --git a/onionr/onionrproofs.py b/onionr/onionrproofs.py
index b6a63d8a..04746508 100644
--- a/onionr/onionrproofs.py
+++ b/onionr/onionrproofs.py
@@ -159,6 +159,9 @@ class POW:
             self.metadata['powRandomToken'] = base64.b64encode(rand).decode()
             payload = json.dumps(self.metadata).encode() + b'\n' + self.data
             token = myCore._crypto.sha3Hash(payload)
+            if type(token) is bytes:
+                # crypto.sha3Hash returns bytes on some older python versions
+                self.puzzle = self.puzzle.encode()
             #print(token)
             if self.puzzle == token[0:self.difficulty]:
                 self.hashing = False