diff --git a/fdroidserver/build.py b/fdroidserver/build.py
index 7e587c9b..464ccf1c 100644
--- a/fdroidserver/build.py
+++ b/fdroidserver/build.py
@@ -78,9 +78,9 @@ def build_server(app, build, vcs, build_dir, output_dir, log_dir, force):
         if not buildserverid:
             buildserverid = subprocess.check_output(['vagrant', 'ssh', '-c',
                                                      'cat /home/vagrant/buildserverid'],
-                                                    cwd='builder').rstrip()
+                                                    cwd='builder').rstrip().decode()
             logging.debug(_('Fetched buildserverid from VM: {buildserverid}')
-                          .format(buildserverid=buildserverid.decode()))
+                          .format(buildserverid=buildserverid))
 
         # Open SSH connection...
         logging.info("Connecting to virtual machine...")