diff --git a/README.md b/README.md
index b34f655..2d88421 100644
--- a/README.md
+++ b/README.md
@@ -891,7 +891,7 @@ Examples:
 
 ## GPIO lock control (optional)
 
-The lock can be controlled via GPIO. To trigger actions, a connection to ground has to be present for at lease 300ms (or to +3.3V for "General input (pull-down)"). <br>
+The lock can be controlled via GPIO. To trigger actions, a connection to ground has to be present for at least 300ms (or to +3.3V for "General input (pull-down)"). <br>
 <br>
 To enable GPIO control, go the the "GPIO Configuration" page where each GPIO can e configured for a specific role:
 - Disabled: The GPIO is disabled