diff --git a/Hardware-API.md b/Hardware-API.md
index dfd4ed9..ce3795d 100644
--- a/Hardware-API.md
+++ b/Hardware-API.md
@@ -172,7 +172,7 @@ TOD: Do we really need 2+ ways to set the value?
 
 ### Constants
 - **for mode:** `Pin.IN`, `Pin.OUT`, `Pin.OPEN_DRAIN`, `Pin.ALT`, `Pin.ALT_OPEN_DRAIN`
-- **for pull:** `Pin.PULL_UP`, `Pin.PULL_DOWN`, _optional:_ `Pin.PULL_UP_STRONG`, `Pin.PULL_DOWN_WEAK`, ...
+- **for pull:** `Pin.PULL_UP`, `Pin.PULL_DOWN`, (no pull is `None`). _optional:_ `Pin.PULL_UP_STRONG`, `Pin.PULL_DOWN_WEAK`, ...
 - **for drive:** `Pin.LOW_POWER`, `Pin.MED_POWER`, `Pin.HIGH_POWER`
 - **for slew:** `Pin.FAST_RISE`, `Pin.SLOW_RISE`
 - **IRQ triggers:** `pin.IRQ_RISING`, `pin.IRQ_FALLING`, `pin.IRQ_HIGH_LEVEL`, `pin.IRQ_LOW_LEVEL`