diff --git a/libraries/AP_NavEKF3/AP_NavEKF3.cpp b/libraries/AP_NavEKF3/AP_NavEKF3.cpp
index ddde1893b4..5f68ddb2a9 100644
--- a/libraries/AP_NavEKF3/AP_NavEKF3.cpp
+++ b/libraries/AP_NavEKF3/AP_NavEKF3.cpp
@@ -360,7 +360,7 @@ const AP_Param::GroupInfo NavEKF3::var_info[] = {
     // @Units: m/s/s/s
     AP_GROUPINFO("ABIAS_P_NSE", 28, NavEKF3, _accelBiasProcessNoise, ABIAS_P_NSE_DEFAULT),
 
-    // 29 previously used for EK2_MAG_P_NSE parameter that has been replaced with EK2_MAGE_P_NSE and EK2_MAGB_P_NSE
+    // 29 previously used for EK2_MAG_P_NSE parameter that has been replaced with EK3_MAGE_P_NSE and EK3_MAGB_P_NSE
 
     // @Param: WIND_P_NSE
     // @DisplayName: Wind velocity process noise (m/s^2)
diff --git a/libraries/AP_NavEKF3/AP_NavEKF3_VehicleStatus.cpp b/libraries/AP_NavEKF3/AP_NavEKF3_VehicleStatus.cpp
index 5766218181..0c7c3b18bc 100644
--- a/libraries/AP_NavEKF3/AP_NavEKF3_VehicleStatus.cpp
+++ b/libraries/AP_NavEKF3/AP_NavEKF3_VehicleStatus.cpp
@@ -84,11 +84,11 @@ bool NavEKF3_core::calcGpsGoodToAlign(void)
         // If the EKF settings require vertical GPS velocity and the receiver is not outputting it, then fail
         gpsVertVelFail = true;
         // if we have a 3D fix with no vertical velocity and
-        // EK2_GPS_TYPE=0 then change it to 1. It means the GPS is not
+        // EK3_GPS_TYPE=0 then change it to 1. It means the GPS is not
         // capable of giving a vertical velocity
         if (_ahrs->get_gps().status() >= AP_GPS::GPS_OK_FIX_3D) {
             frontend->_fusionModeGPS.set(1);
-            GCS_MAVLINK::send_statustext_all(MAV_SEVERITY_WARNING, "EK2: Changed EK2_GPS_TYPE to 1");
+            GCS_MAVLINK::send_statustext_all(MAV_SEVERITY_WARNING, "EK3: Changed EK3_GPS_TYPE to 1");
         }
     } else {
         gpsVertVelFail = false;
diff --git a/libraries/AP_NavEKF3/AP_NavEKF3_core.cpp b/libraries/AP_NavEKF3/AP_NavEKF3_core.cpp
index f3be634be9..59065ef767 100644
--- a/libraries/AP_NavEKF3/AP_NavEKF3_core.cpp
+++ b/libraries/AP_NavEKF3/AP_NavEKF3_core.cpp
@@ -16,25 +16,25 @@ extern const AP_HAL::HAL& hal;
 NavEKF3_core::NavEKF3_core(void) :
     stateStruct(*reinterpret_cast<struct state_elements *>(&statesArray)),
 
-    _perf_UpdateFilter(hal.util->perf_alloc(AP_HAL::Util::PC_ELAPSED, "EK2_UpdateFilter")),
-    _perf_CovariancePrediction(hal.util->perf_alloc(AP_HAL::Util::PC_ELAPSED, "EK2_CovariancePrediction")),
-    _perf_FuseVelPosNED(hal.util->perf_alloc(AP_HAL::Util::PC_ELAPSED, "EK2_FuseVelPosNED")),
-    _perf_FuseMagnetometer(hal.util->perf_alloc(AP_HAL::Util::PC_ELAPSED, "EK2_FuseMagnetometer")),
-    _perf_FuseAirspeed(hal.util->perf_alloc(AP_HAL::Util::PC_ELAPSED, "EK2_FuseAirspeed")),
-    _perf_FuseSideslip(hal.util->perf_alloc(AP_HAL::Util::PC_ELAPSED, "EK2_FuseSideslip")),
-    _perf_TerrainOffset(hal.util->perf_alloc(AP_HAL::Util::PC_ELAPSED, "EK2_TerrainOffset")),
-    _perf_FuseOptFlow(hal.util->perf_alloc(AP_HAL::Util::PC_ELAPSED, "EK2_FuseOptFlow"))
+    _perf_UpdateFilter(hal.util->perf_alloc(AP_HAL::Util::PC_ELAPSED, "EK3_UpdateFilter")),
+    _perf_CovariancePrediction(hal.util->perf_alloc(AP_HAL::Util::PC_ELAPSED, "EK3_CovariancePrediction")),
+    _perf_FuseVelPosNED(hal.util->perf_alloc(AP_HAL::Util::PC_ELAPSED, "EK3_FuseVelPosNED")),
+    _perf_FuseMagnetometer(hal.util->perf_alloc(AP_HAL::Util::PC_ELAPSED, "EK3_FuseMagnetometer")),
+    _perf_FuseAirspeed(hal.util->perf_alloc(AP_HAL::Util::PC_ELAPSED, "EK3_FuseAirspeed")),
+    _perf_FuseSideslip(hal.util->perf_alloc(AP_HAL::Util::PC_ELAPSED, "EK3_FuseSideslip")),
+    _perf_TerrainOffset(hal.util->perf_alloc(AP_HAL::Util::PC_ELAPSED, "EK3_TerrainOffset")),
+    _perf_FuseOptFlow(hal.util->perf_alloc(AP_HAL::Util::PC_ELAPSED, "EK3_FuseOptFlow"))
 {
-    _perf_test[0] = hal.util->perf_alloc(AP_HAL::Util::PC_ELAPSED, "EK2_Test0");
-    _perf_test[1] = hal.util->perf_alloc(AP_HAL::Util::PC_ELAPSED, "EK2_Test1");
-    _perf_test[2] = hal.util->perf_alloc(AP_HAL::Util::PC_ELAPSED, "EK2_Test2");
-    _perf_test[3] = hal.util->perf_alloc(AP_HAL::Util::PC_ELAPSED, "EK2_Test3");
-    _perf_test[4] = hal.util->perf_alloc(AP_HAL::Util::PC_ELAPSED, "EK2_Test4");
-    _perf_test[5] = hal.util->perf_alloc(AP_HAL::Util::PC_ELAPSED, "EK2_Test5");
-    _perf_test[6] = hal.util->perf_alloc(AP_HAL::Util::PC_ELAPSED, "EK2_Test6");
-    _perf_test[7] = hal.util->perf_alloc(AP_HAL::Util::PC_ELAPSED, "EK2_Test7");
-    _perf_test[8] = hal.util->perf_alloc(AP_HAL::Util::PC_ELAPSED, "EK2_Test8");
-    _perf_test[9] = hal.util->perf_alloc(AP_HAL::Util::PC_ELAPSED, "EK2_Test9");
+    _perf_test[0] = hal.util->perf_alloc(AP_HAL::Util::PC_ELAPSED, "EK3_Test0");
+    _perf_test[1] = hal.util->perf_alloc(AP_HAL::Util::PC_ELAPSED, "EK3_Test1");
+    _perf_test[2] = hal.util->perf_alloc(AP_HAL::Util::PC_ELAPSED, "EK3_Test2");
+    _perf_test[3] = hal.util->perf_alloc(AP_HAL::Util::PC_ELAPSED, "EK3_Test3");
+    _perf_test[4] = hal.util->perf_alloc(AP_HAL::Util::PC_ELAPSED, "EK3_Test4");
+    _perf_test[5] = hal.util->perf_alloc(AP_HAL::Util::PC_ELAPSED, "EK3_Test5");
+    _perf_test[6] = hal.util->perf_alloc(AP_HAL::Util::PC_ELAPSED, "EK3_Test6");
+    _perf_test[7] = hal.util->perf_alloc(AP_HAL::Util::PC_ELAPSED, "EK3_Test7");
+    _perf_test[8] = hal.util->perf_alloc(AP_HAL::Util::PC_ELAPSED, "EK3_Test8");
+    _perf_test[9] = hal.util->perf_alloc(AP_HAL::Util::PC_ELAPSED, "EK3_Test9");
     firstInitTime_ms = 0;
     lastInitFailReport_ms = 0;
 }
@@ -508,7 +508,7 @@ void NavEKF3_core::UpdateFilter(bool predict)
     }
 
     // start the timer used for load measurement
-#if EK2_DISABLE_INTERRUPTS
+#if EK3_DISABLE_INTERRUPTS
     irqstate_t istate = irqsave();
 #endif
     hal.util->perf_begin(_perf_UpdateFilter);
@@ -556,7 +556,7 @@ void NavEKF3_core::UpdateFilter(bool predict)
 
     // stop the timer used for load measurement
     hal.util->perf_end(_perf_UpdateFilter);
-#if EK2_DISABLE_INTERRUPTS
+#if EK3_DISABLE_INTERRUPTS
     irqrestore(istate);
 #endif
 }
diff --git a/libraries/AP_NavEKF3/AP_NavEKF3_core.h b/libraries/AP_NavEKF3/AP_NavEKF3_core.h
index 8c4138cd66..eca166cc62 100644
--- a/libraries/AP_NavEKF3/AP_NavEKF3_core.h
+++ b/libraries/AP_NavEKF3/AP_NavEKF3_core.h
@@ -21,7 +21,7 @@
 
 #pragma GCC optimize("O3")
 
-#define EK2_DISABLE_INTERRUPTS 0
+#define EK3_DISABLE_INTERRUPTS 0
 
 
 #include <AP_Math/AP_Math.h>