diff --git a/ArduCopter/Copter.cpp b/ArduCopter/Copter.cpp
index 8b995ea0b1..a52905f159 100644
--- a/ArduCopter/Copter.cpp
+++ b/ArduCopter/Copter.cpp
@@ -144,7 +144,7 @@ const AP_Scheduler::Task Copter::scheduler_tasks[] = {
     SCHED_TASK(throttle_loop,         50,     75,  6),
     SCHED_TASK_CLASS(AP_GPS,               &copter.gps,                 update,          50, 200,   9),
 #if AP_OPTICALFLOW_ENABLED
-    SCHED_TASK_CLASS(OpticalFlow,          &copter.optflow,             update,         200, 160,  12),
+    SCHED_TASK_CLASS(AP_OpticalFlow,          &copter.optflow,             update,         200, 160,  12),
 #endif
     SCHED_TASK(update_batt_compass,   10,    120, 15),
     SCHED_TASK_CLASS(RC_Channels, (RC_Channels*)&copter.g2.rc_channels, read_aux_all,    10,  50,  18),
diff --git a/ArduCopter/Copter.h b/ArduCopter/Copter.h
index 98ac26588c..6fb0ea93b3 100644
--- a/ArduCopter/Copter.h
+++ b/ArduCopter/Copter.h
@@ -310,7 +310,7 @@ private:
 
     // Optical flow sensor
 #if AP_OPTICALFLOW_ENABLED
-    OpticalFlow optflow;
+    AP_OpticalFlow optflow;
 #endif
 
     // system time in milliseconds of last recorded yaw reset from ekf
diff --git a/ArduCopter/GCS_Copter.cpp b/ArduCopter/GCS_Copter.cpp
index db0737e89e..809216e1f0 100644
--- a/ArduCopter/GCS_Copter.cpp
+++ b/ArduCopter/GCS_Copter.cpp
@@ -115,7 +115,7 @@ void GCS_Copter::update_vehicle_sensor_status_flags(void)
 #endif
 
 #if AP_OPTICALFLOW_ENABLED
-    const OpticalFlow *optflow = AP::opticalflow();
+    const AP_OpticalFlow *optflow = AP::opticalflow();
     if (optflow && optflow->enabled()) {
         control_sensors_present |= MAV_SYS_STATUS_SENSOR_OPTICAL_FLOW;
         control_sensors_enabled |= MAV_SYS_STATUS_SENSOR_OPTICAL_FLOW;
diff --git a/ArduCopter/Parameters.cpp b/ArduCopter/Parameters.cpp
index 9c5c724f88..db8d5c582b 100644
--- a/ArduCopter/Parameters.cpp
+++ b/ArduCopter/Parameters.cpp
@@ -674,7 +674,7 @@ const AP_Param::Info Copter::var_info[] = {
 #if AP_OPTICALFLOW_ENABLED
     // @Group: FLOW
     // @Path: ../libraries/AP_OpticalFlow/AP_OpticalFlow.cpp
-    GOBJECT(optflow,   "FLOW", OpticalFlow),
+    GOBJECT(optflow,   "FLOW", AP_OpticalFlow),
 #endif
 
 #if PRECISION_LANDING == ENABLED