diff --git a/sw/airborne/nav.c b/sw/airborne/nav.c
index 8ebaab9c8b..d4fb4bfe88 100644
--- a/sw/airborne/nav.c
+++ b/sw/airborne/nav.c
@@ -187,7 +187,7 @@ static float qdr;
 #define Follow(_ac_id, _distance, _height) { \
   struct ac_info_ * ac = get_ac_info(_ac_id); \
   vertical_mode = VERTICAL_MODE_AUTO_ALT; \
-  nav_altitude = Max(ac->alt + _height, SECURITY_ALT); \
+  nav_altitude = Max(ac->alt + _height, ground_alt+SECURITY_HEIGHT); \
   float alpha = M_PI/2 - ac->course; \
   fly_to_xy(ac->east - _distance*cos(alpha), ac->north - _distance*sin(alpha)); \
 }
@@ -477,7 +477,7 @@ void nav_home(void) {
   /** Nominal speed */ 
   nav_pitch = 0.;
   vertical_mode = VERTICAL_MODE_AUTO_ALT;
-  nav_altitude = ground_alt+50;
+  nav_altitude = ground_alt+SECURITY_HEIGHT;
   compute_dist2_to_home();
   dist2_to_wp = dist2_to_home;
 }
diff --git a/sw/tools/extract_makefile.ml b/sw/tools/extract_makefile.ml
index c24800e2df..aeed37d90f 100644
--- a/sw/tools/extract_makefile.ml
+++ b/sw/tools/extract_makefile.ml
@@ -6,13 +6,13 @@ let _ =
   printf "# This file has been generated from %s by sw/tools/extract_makefile\n" f;
   printf "# Please DO NOT EDIT\n";
   List.iter (fun x ->
-    if ExtXml.tag_is x "makefile" then
-      begin
-	try
-	  printf "\n# makefile target '%s'\n" (Xml.attrib x "target")
-	with _ -> ()
-      end;
-    match Xml.children x with
-      [Xml.PCData s] -> printf "%s\n" s
-    | _ -> fprintf stderr "Warning: wrong makefile section in '%s': %s\n" f (Xml.to_string_fmt x))
+    if ExtXml.tag_is x "makefile" then begin
+      begin try
+	printf "\n# makefile target '%s'\n" (Xml.attrib x "target")
+      with _ -> () end;
+      match Xml.children x with
+	[Xml.PCData s] -> printf "%s\n" s
+      | _ -> fprintf stderr "Warning: wrong makefile section in '%s': %s\n" f (Xml.to_string_fmt x)
+    end)
     (Xml.children xml)
+    
diff --git a/sw/tools/gen_flight_plan.ml b/sw/tools/gen_flight_plan.ml
index 445641ddcc..23997ba561 100644
--- a/sw/tools/gen_flight_plan.ml
+++ b/sw/tools/gen_flight_plan.ml
@@ -713,6 +713,7 @@ let _ =
       Xml2h.define "NB_WAYPOINT" (string_of_int (List.length waypoints));
 
       Xml2h.define "GROUND_ALT" (sof !ground_alt);
+      Xml2h.define "SECURITY_HEIGHT" (sof !security_height);
       Xml2h.define "SECURITY_ALT" (sof (!security_height +. !ground_alt));
       Xml2h.define "MAX_DIST_FROM_HOME" (sof mdfh);