diff --git a/libraries/AP_IRLock/AP_IRLock_I2C.cpp b/libraries/AP_IRLock/AP_IRLock_I2C.cpp
index 4b8da6d0bc..f1f6de1e57 100644
--- a/libraries/AP_IRLock/AP_IRLock_I2C.cpp
+++ b/libraries/AP_IRLock/AP_IRLock_I2C.cpp
@@ -25,7 +25,6 @@
 #include <stdio.h>
 #include <utility>
 #include <AP_HAL/I2CDevice.h>
-#include <AP_Common/Semaphore.h>
 
 extern const AP_HAL::HAL& hal;