diff --git a/components/mpas-ocean/src/tracer_groups/Registry_activeTracers.xml b/components/mpas-ocean/src/tracer_groups/Registry_activeTracers.xml
index 40842485041c..ca01d7905e03 100644
--- a/components/mpas-ocean/src/tracer_groups/Registry_activeTracers.xml
+++ b/components/mpas-ocean/src/tracer_groups/Registry_activeTracers.xml
@@ -61,7 +61,7 @@
 
 	<var_struct name="state" time_levs="2">
 		<var_struct name="tracers" time_levs="2">
-			<var_array name="activeTracers" dimensions="nVertLevels nCells Time" type="real" packages="activeTracersPKG" missing_value="FILLVAL" missing_value_mask="cellMask">
+			<var_array name="activeTracers" dimensions="nVertLevels nCells Time" type="real" packages="activeTracersPKG">
 				<var name="temperature" array_group="activeGRP" units="C"
 			 description="potential temperature"
 			 	/>
@@ -74,7 +74,7 @@
 
 	<var_struct name="tend" time_levs="1">
 		<var_struct name="tracersTend" time_levs="1">
-			<var_array name="activeTracersTend" type="real" dimensions="nVertLevels nCells Time" packages="activeTracersPKG" missing_value="FILLVAL" missing_value_mask="cellMask">
+			<var_array name="activeTracersTend" type="real" dimensions="nVertLevels nCells Time" packages="activeTracersPKG">
 				<var name="temperatureTend" array_group="activeGRP" units="C s^-1"
 			 description="time tendency of potential temperature"
 				/>