diff --git a/ArduCopter/Parameters.cpp b/ArduCopter/Parameters.cpp
index 22a539f203..fb5b9a1f5b 100644
--- a/ArduCopter/Parameters.cpp
+++ b/ArduCopter/Parameters.cpp
@@ -354,7 +354,7 @@ const AP_Param::Info Copter::var_info[] = {
 
     // @Param: DISARM_DELAY
     // @DisplayName: Disarm delay
-    // @Description: Delay before automatic disarm in seconds. A value of zero disables auto disarm.
+    // @Description: Delay before automatic disarm in seconds after landing touchdown detection. A value of zero disables auto disarm. If Emergency Motor stop active, delay time is half this value.
     // @Units: s
     // @Range: 0 127
     // @User: Advanced