diff --git a/Systems/a320-adr.xml b/Systems/a320-adr.xml
index 9896d49b..b1ef10f0 100644
--- a/Systems/a320-adr.xml
+++ b/Systems/a320-adr.xml
@@ -923,7 +923,7 @@
 			</clipto>
 		</pure_gain>
 
-		<fcs_function name="/instrumentation/radar-altimeter-difference">
+		<fcs_function name="/instrumentation/radar-altimeter-difference-ft">
 			<function>
 			   <abs>
 					<difference>
diff --git a/Systems/a320-fwc.xml b/Systems/a320-fwc.xml
index 09ab1065..de676136 100644
--- a/Systems/a320-fwc.xml
+++ b/Systems/a320-fwc.xml
@@ -2326,7 +2326,7 @@
 					/it-autoflight/output/ap1 eq 0
 					/it-autoflight/output/ap2 eq 0			    
 			    </test>
-				/instrumentation/radar-altimeter-difference gt 15
+				/instrumentation/radar-altimeter-difference-ft gt 15
 				<!-- TODO 
 				- Localizer deviation excessive
 				- Loss of localizer signal