diff --git a/Makefile.ac b/Makefile.ac
index 91480c6b79..0f3132a51e 100644
--- a/Makefile.ac
+++ b/Makefile.ac
@@ -67,6 +67,8 @@ demo:
 
 all_ac_h: $(AIRFRAME_H) $(RADIO_H) $(FLIGHT_PLAN_H) $(FLIGHT_PLAN_XML) $(SETTINGS_H) $(TUNING_H) $(MAKEFILE_AC) $(PERIODIC_H) $(MODULES_H)
 
+makefile_ac: $(MAKEFILE_AC)
+
 $(AIRFRAME_H) : $(CONF)/$(AIRFRAME_XML) $(CONF_XML)
 	@echo BUILD $@
 	$(Q)$(TOOLS)/gen_airframe.out $(AC_ID) $(AIRCRAFT) $(MD5SUM) $< > /tmp/airframe.h
@@ -80,7 +82,10 @@ $(RADIO_H) : $(CONF)/$(RADIO) $(CONF_XML) $(TOOLS)/gen_radio.out
 	$(Q)mv /tmp/radio.h $@
 	$(Q)cp $< $(AIRCRAFT_CONF_DIR)/radios
 
-include $(MAKEFILE_AC)
+ifeq ($(MAKECMDGOALS),all_ac_h) 
+-include $(MAKEFILE_AC)
+endif
+
 $(PERIODIC_H) : $(MESSAGES_XML) $(CONF_XML) $(CONF)/$(TELEMETRY) $(MAKEFILE_AC)
 	@echo BUILD $@
 	$(Q)$(TOOLS)/gen_periodic.out $(MESSAGES_XML) $(CONF)/$(TELEMETRY) $(PERIODIC_FREQ) > $@
@@ -113,6 +118,7 @@ $(TUNING_H) : $(SETTINGS_XMLS) $(CONF_XML) $(TOOLS)/gen_tuning.out
 
 $(MAKEFILE_AC) : $(CONF)/$(AIRFRAME_XML)
 	@echo BUILD $@
+	$(Q)mkdir -p $(ACINCLUDE)
 	$(Q)$(TOOLS)/extract_makefile.out $< $(MODULES_DIR) > $@
 
 $(MODULES_H) : $(CONF)/$(AIRFRAME_XML) $(TOOLS)/gen_modules.out $(CONF)/modules/*.xml
diff --git a/sw/tools/gen_aircraft.ml b/sw/tools/gen_aircraft.ml
index 2c0e011c87..ae3f030c2b 100644
--- a/sw/tools/gen_aircraft.ml
+++ b/sw/tools/gen_aircraft.ml
@@ -97,9 +97,15 @@ let _ =
   Printf.fprintf f "%s\n" md5sum;
   close_out f;
   
-  let c = sprintf "make -f Makefile.ac AIRCRAFT=%s AC_ID=%s AIRFRAME_XML=%s RADIO=%s FLIGHT_PLAN=%s TELEMETRY=%s SETTINGS=\"%s\" MD5SUM=\"%s\" all_ac_h" aircraft (value "ac_id") (value "airframe") (value "radio") (value "flight_plan") (value "telemetry") settings md5sum in
-  begin (** Quiet is speficied in the Makefile *)
-    try if Sys.getenv "Q" <> "@" then raise Not_found with
-      Not_found -> prerr_endline c
-  end;
-  exit (Sys.command c)
+  let make = fun target ->
+    let c = sprintf "make -f Makefile.ac AIRCRAFT=%s AC_ID=%s AIRFRAME_XML=%s RADIO=%s FLIGHT_PLAN=%s TELEMETRY=%s SETTINGS=\"%s\" MD5SUM=\"%s\" %s" aircraft (value "ac_id") (value "airframe") (value "radio") (value "flight_plan") (value "telemetry") settings md5sum target in
+    prerr_endline c;
+    begin (** Quiet is speficied in the Makefile *)
+      try if Sys.getenv "Q" <> "@" then raise Not_found with
+	Not_found -> prerr_endline c
+    end;
+    let returned_code = Sys.command c in
+    if returned_code <> 0 then
+      exit returned_code in
+  make "makefile_ac";
+  make "all_ac_h"