diff --git a/libraries/AP_NavEKF/AP_NavEKF.cpp b/libraries/AP_NavEKF/AP_NavEKF.cpp
index 6aa56edf41..a82298fa53 100644
--- a/libraries/AP_NavEKF/AP_NavEKF.cpp
+++ b/libraries/AP_NavEKF/AP_NavEKF.cpp
@@ -788,7 +788,7 @@ void NavEKF::SelectVelPosFusion()
             fuseVelData = false;
             fusePosData = false;
         }
-    } else if (constPosMode ) {
+    } else if (constPosMode && covPredStep) {
         // in constant position mode use synthetic position measurements set to zero
         // only fuse synthetic measurements when rate of change of velocity is less than 0.5g to reduce attitude errors due to launch acceleration
         // do not use velocity fusion to reduce the effect of movement on attitude
@@ -798,7 +798,7 @@ void NavEKF::SelectVelPosFusion()
             fusePosData = false;
         }
         fuseVelData = false;
-    } else if (constVelMode) {
+    } else if (constVelMode && covPredStep) {
         // In constant velocity mode we fuse the last valid velocity vector
         // Reset the stored velocity vector when we enter the mode
         if (constVelMode && !lastConstVelMode) {