diff --git a/easywks/files.py b/easywks/files.py
index 59aa6af..4bb282a 100644
--- a/easywks/files.py
+++ b/easywks/files.py
@@ -99,7 +99,7 @@ def write_public_key(domain, user, key, revoked):
     danefile = os.path.join(Config.working_directory, domain, 'dane', dane)
     joined = bytes(key) + b''.join([bytes(k) for k in revoked])
     _locked_write(keyfile, joined, binary=True)
-    _locked_write(danefile, key, binary=True)
+    _locked_write(danefile, bytes(key), binary=True)
     dane_notify(domain)