diff --git a/libraries/AP_AHRS/AP_AHRS.cpp b/libraries/AP_AHRS/AP_AHRS.cpp
index 901a6bb584..0d082fabe5 100644
--- a/libraries/AP_AHRS/AP_AHRS.cpp
+++ b/libraries/AP_AHRS/AP_AHRS.cpp
@@ -117,7 +117,7 @@ const AP_Param::GroupInfo AP_AHRS::var_info[] PROGMEM = {
     // @Description: This controls whether the NavEKF Kalman filter is used for attitude and position estimation
     // @Values: 0:Disabled,1:Enabled
     // @User: Advanced
-    AP_GROUPINFO("EKF_USE",  13, AP_AHRS, _ekf_use, 0),
+    AP_GROUPINFO("EKF_USE",  13, AP_AHRS, _ekf_use, AHRS_EKF_USE_DEFAULT),
 #endif
 
     AP_GROUPEND
diff --git a/libraries/AP_AHRS/AP_AHRS.h b/libraries/AP_AHRS/AP_AHRS.h
index 31457c423f..8e5ae3b30f 100644
--- a/libraries/AP_AHRS/AP_AHRS.h
+++ b/libraries/AP_AHRS/AP_AHRS.h
@@ -31,6 +31,13 @@
 #include <AP_Baro.h>
 #include <AP_Param.h>
 
+// Copter defaults to EKF on by default, all others off
+#if APM_BUILD_TYPE(APM_BUILD_ArduCopter)
+#define AHRS_EKF_USE_DEFAULT    1
+#else
+#define AHRS_EKF_USE_DEFAULT    0
+#endif
+
 #define AP_AHRS_TRIM_LIMIT 10.0f        // maximum trim angle in degrees
 #define AP_AHRS_RP_P_MIN   0.05f        // minimum value for AHRS_RP_P parameter
 #define AP_AHRS_YAW_P_MIN  0.05f        // minimum value for AHRS_YAW_P parameter