--- a/duplicity/backends/giobackend.py
+++ b/duplicity/backends/giobackend.py
@@ -34,7 +34,7 @@ def ensure_dbus():
     # environment points to it.
     if "DBUS_SESSION_BUS_ADDRESS" not in os.environ:
         p = subprocess.Popen(["dbus-launch"], stdout=subprocess.PIPE, universal_newlines=True)
-        output = p.communicate()[0]
+        output = p.communicate()[0].decode("utf8", errors="replace")
         lines = output.split("\n")
         for line in lines:
             parts = line.split("=", 1)
