diff --git a/ArduSub/ArduSub.cpp b/ArduSub/ArduSub.cpp
index 3f0134ad0e..e1c7b20af6 100644
--- a/ArduSub/ArduSub.cpp
+++ b/ArduSub/ArduSub.cpp
@@ -95,7 +95,7 @@ const AP_Scheduler::Task Sub::scheduler_tasks[] = {
     SCHED_TASK_CLASS(AP_Logger,           &sub.logger,       periodic_tasks,     400, 300,  57),
     SCHED_TASK_CLASS(AP_InertialSensor,   &sub.ins,          periodic,           400,  50,  60),
     SCHED_TASK_CLASS(AP_Scheduler,        &sub.scheduler,    update_logging,     0.1,  75,  63),
-#if RPM_ENABLED == ENABLED
+#if AP_RPM_ENABLED
     SCHED_TASK_CLASS(AP_RPM,              &sub.rpm_sensor,   update,              10, 200,  66),
 #endif
     SCHED_TASK(terrain_update,        10,    100,  72),
diff --git a/ArduSub/GCS_Mavlink.cpp b/ArduSub/GCS_Mavlink.cpp
index d25c27f475..d526503b2f 100644
--- a/ArduSub/GCS_Mavlink.cpp
+++ b/ArduSub/GCS_Mavlink.cpp
@@ -387,7 +387,7 @@ static const ap_message STREAM_EXTRA3_msgs[] = {
     MSG_MAG_CAL_PROGRESS,
     MSG_EKF_STATUS_REPORT,
     MSG_VIBRATION,
-#if RPM_ENABLED == ENABLED
+#if AP_RPM_ENABLED
     MSG_RPM,
 #endif
     MSG_ESC_TELEMETRY,
diff --git a/ArduSub/Parameters.cpp b/ArduSub/Parameters.cpp
index 27cf80d582..a9025addf5 100644
--- a/ArduSub/Parameters.cpp
+++ b/ArduSub/Parameters.cpp
@@ -599,7 +599,7 @@ const AP_Param::Info Sub::var_info[] = {
     GOBJECT(optflow,   "FLOW", AP_OpticalFlow),
 #endif
 
-#if RPM_ENABLED == ENABLED
+#if AP_RPM_ENABLED
     // @Group: RPM
     // @Path: ../libraries/AP_RPM/AP_RPM.cpp
     GOBJECT(rpm_sensor, "RPM", AP_RPM),
diff --git a/ArduSub/Sub.h b/ArduSub/Sub.h
index e3d0240457..2bb1c402c5 100644
--- a/ArduSub/Sub.h
+++ b/ArduSub/Sub.h
@@ -81,7 +81,9 @@
 #include <AP_RCMapper/AP_RCMapper.h>        // RC input mapping library
 #endif
 
-#if RPM_ENABLED == ENABLED
+#include <AP_RPM/AP_RPM_config.h>
+
+#if AP_RPM_ENABLED
 #include <AP_RPM/AP_RPM.h>
 #endif
 
@@ -151,7 +153,7 @@ private:
         LowPassFilterFloat alt_cm_filt; // altitude filter
     } rangefinder_state = { false, false, 0, 0 };
 
-#if RPM_ENABLED == ENABLED
+#if AP_RPM_ENABLED
     AP_RPM rpm_sensor;
 #endif
 
diff --git a/ArduSub/config.h b/ArduSub/config.h
index a7bb740cce..322bd5b9aa 100644
--- a/ArduSub/config.h
+++ b/ArduSub/config.h
@@ -34,14 +34,6 @@
 # define CIRCLE_NAV_ENABLED ENABLED
 #endif
 
-//////////////////////////////////////////////////////////////////////////////
-// RPM
-//
-
-#ifndef RPM_ENABLED
-# define RPM_ENABLED DISABLED
-#endif
-
 //////////////////////////////////////////////////////////////////////////////
 // RCMAP
 //
diff --git a/ArduSub/system.cpp b/ArduSub/system.cpp
index e3d398f053..6fa584378e 100644
--- a/ArduSub/system.cpp
+++ b/ArduSub/system.cpp
@@ -137,7 +137,7 @@ void Sub::init_ardupilot()
 #endif
 
     // initialise AP_RPM library
-#if RPM_ENABLED == ENABLED
+#if AP_RPM_ENABLED
     rpm_sensor.init();
 #endif