diff --git a/libraries/AP_DAL/AP_DAL.cpp b/libraries/AP_DAL/AP_DAL.cpp
index 4d6a1f9bd6..2a8cba1183 100644
--- a/libraries/AP_DAL/AP_DAL.cpp
+++ b/libraries/AP_DAL/AP_DAL.cpp
@@ -8,6 +8,7 @@
 #include <AP_WheelEncoder/AP_WheelEncoder.h>
 #include <AP_Vehicle/AP_Vehicle_Type.h>
 #include <AP_NavEKF3/AP_NavEKF3_feature.h>
+#include <AP_NavEKF/AP_Nav_Common.h>
 
 #if APM_BUILD_TYPE(APM_BUILD_Replay)
 #include <AP_NavEKF2/AP_NavEKF2.h>
diff --git a/libraries/AP_NavEKF/AP_Nav_Common.h b/libraries/AP_NavEKF/AP_Nav_Common.h
index a24f96e86e..5959fa8d81 100644
--- a/libraries/AP_NavEKF/AP_Nav_Common.h
+++ b/libraries/AP_NavEKF/AP_Nav_Common.h
@@ -19,6 +19,8 @@
 #include <stdint.h>
 #include <AP_Math/AP_Math.h>
 
+#define MAX_EKF_CORES     3 // maximum allowed EKF Cores to be instantiated
+
 // enumeration corresponding to buts within nav_filter_status union.
 // Only used for documentation purposes.
 enum class NavFilterStatusBit {
diff --git a/libraries/AP_NavEKF3/AP_NavEKF3.h b/libraries/AP_NavEKF3/AP_NavEKF3.h
index 6bfba2ee17..73d7678b9d 100644
--- a/libraries/AP_NavEKF3/AP_NavEKF3.h
+++ b/libraries/AP_NavEKF3/AP_NavEKF3.h
@@ -530,7 +530,6 @@ private:
         float core_delta;             // the amount of D position change between cores when a change happened
     } pos_down_reset_data;
 
-#define MAX_EKF_CORES     3 // maximum allowed EKF Cores to be instantiated
 #define CORE_ERR_LIM      1 // -LIM to LIM relative error range for a core
 #define BETTER_THRESH   0.5 // a lane should have this much relative error difference to be considered for overriding a healthy primary core