Fix "error writing fixed header" bug

4 jobs for passoft_py3_bugs in 41 seconds (queued for 3 seconds)
Status Name Job ID Coverage
  Test
passed linting #2661
passoft

00:00:41

passed python3.6 #2662
passoft

00:00:36

passed python3.7 #2663
passoft

00:00:34

passed python3.8 #2664
passoft

00:00:32