Systemd-swap: Regression with old config. Unable to start "systemd-swap: line 78: read: 1s: invalid timeout specification"

OS: Arch Linux
Version: 4.1.0-1

/etc/systemd/swap.conf compare to .pacnew conf

< swapfc_frequency=1s         # How often check free swap space
---
> swapfc_frequency=1          # How often to check free swap space

top shows constantly 30++% CPU usage

1662996 root       1 -19    7512   2552   1836 S  32.0   0.0   0:12.29 bash systemd-swap start                                                                                                                  

Systemd Journal flooded infinitely with this message

Jun 08 23:17:32 shingetsu systemd-swap[4191261]: /usr/bin/systemd-swap: line 78: read: 1s: invalid timeout specification
Jun 08 23:17:32 shingetsu systemd-swap[4191261]: /usr/bin/systemd-swap: line 78: read: 1s: invalid timeout specification
Jun 08 23:17:32 shingetsu systemd-swap[4191261]: /usr/bin/systemd-swap: line 78: read: 1s: invalid timeout specification
Jun 08 23:17:32 shingetsu systemd-swap[4191261]: /usr/bin/systemd-swap: line 78: read: 1s: invalid timeout specification
Jun 08 23:17:32 shingetsu systemd-swap[4191261]: /usr/bin/systemd-swap: line 78: read: 1s: invalid timeout specification