diff --git a/deluge/core/preferencesmanager.py b/deluge/core/preferencesmanager.py
index e4027b24f..4f8cc7ca3 100644
--- a/deluge/core/preferencesmanager.py
+++ b/deluge/core/preferencesmanager.py
@@ -465,9 +465,9 @@ class PreferencesManager(component.Component):
             if v["type"]:
                 proxy_settings = lt.proxy_settings()
                 proxy_settings.type = lt.proxy_type(v["type"])
-                proxy_settings.username = v["username"]
-                proxy_settings.password = v["password"]
-                proxy_settings.hostname = v["hostname"]
+                proxy_settings.username = str(v["username"])
+                proxy_settings.password = str(v["password"])
+                proxy_settings.hostname = str(v["hostname"])
                 proxy_settings.port = v["port"]
                 log.debug("setting %s proxy settings", k)
                 getattr(self.session, "set_%s_proxy" % k)(proxy_settings)