diff --git a/ArduSub/wscript b/ArduSub/wscript
index c6368f13de..59e9a78702 100644
--- a/ArduSub/wscript
+++ b/ArduSub/wscript
@@ -32,6 +32,7 @@ def build(bld):
             'AP_RSSI',
             'AP_Relay',
             'AP_ServoRelayEvents',
+            'AP_WaterDetector',
         ],
         use='mavlink',
     )