diff --git a/deluge/plugins/Blocklist/deluge/plugins/blocklist/detect.py b/deluge/plugins/Blocklist/deluge/plugins/blocklist/detect.py
index 9ed960adb..262d5de4f 100644
--- a/deluge/plugins/Blocklist/deluge/plugins/blocklist/detect.py
+++ b/deluge/plugins/Blocklist/deluge/plugins/blocklist/detect.py
@@ -12,7 +12,7 @@ from __future__ import unicode_literals
 from .decompressers import BZipped2, GZipped, Zipped
 from .readers import EmuleReader, PeerGuardianReader, SafePeerReader
 
-COMPRESSION_TYPES = {'PK': 'Zip', '\x1f\x8b': 'GZip', 'BZ': 'BZip2'}
+COMPRESSION_TYPES = {b'PK': 'Zip', b'\x1f\x8b': 'GZip', b'BZ': 'BZip2'}
 
 DECOMPRESSERS = {'Zip': Zipped, 'GZip': GZipped, 'BZip2': BZipped2}