diff --git a/Aircraft/Generic/generic-autopilot-helper.xml b/Aircraft/Generic/generic-autopilot-helper.xml
index 94ebb1ba3..9c05e0f25 100644
--- a/Aircraft/Generic/generic-autopilot-helper.xml
+++ b/Aircraft/Generic/generic-autopilot-helper.xml
@@ -116,7 +116,7 @@
   <filter>
     <name>static port pressure rate computer</name>
     <debug>false</debug>
-    <type>differential</type>
+    <type>derivative</type>
     <input>systems/static[0]/pressure-inhg</input>
     <output>autopilot/internal/pressure-rate</output>
     <filter-time>1.0</filter-time>
diff --git a/preferences.xml b/preferences.xml
index 206e78511..38dc73a39 100644
--- a/preferences.xml
+++ b/preferences.xml
@@ -270,11 +270,11 @@ Started September 2000 by David Megginson, david@megginson.com
     <path>Aircraft/Generic/generic-autopilot.xml</path>
    </autopilot>
    <!-- 
-   to be enabled when the hard coded helpers are gone
+   replace the hard coded helpers, which are gone now
+   -->
    <autopilot>
     <path>Aircraft/Generic/generic-autopilot-helper.xml</path>
    </autopilot>
-   -->
   </systems>
   <instrumentation>
    <path>Aircraft/Generic/generic-instrumentation.xml</path>