diff --git a/Makefile.ac b/Makefile.ac
index fdd11d5da3..22b883e59b 100644
--- a/Makefile.ac
+++ b/Makefile.ac
@@ -158,7 +158,7 @@ $(SETTINGS_TELEMETRY) : $(PERIODIC_H)
 jsbsim jsbsim.compile: jsbsim.ac_h
 	cd $(AIRBORNE); $(MAKE) TARGET=jsbsim ARCHI=jsbsim ARCH=jsbsim all
 
-sim sim.compile: sim.ac_h
+sim sim.compile: sim.ac_h print_version
 	cd $(AIRBORNE); $(MAKE) TARGET=sim ARCHI=sim ARCH=sim all
 
 # Rules for backward compatibility (old guys are used to !)
diff --git a/sw/airborne/Makefile b/sw/airborne/Makefile
index ae60d2915f..0dd7b7f31c 100644
--- a/sw/airborne/Makefile
+++ b/sw/airborne/Makefile
@@ -55,13 +55,6 @@ ifneq ($(MAKECMDGOALS),clean)
   $(TARGET).srcs := $(sort $($(TARGET).srcs))
 endif
 
-# check for obsolete MODEM_UART_NR and GPS_UART_NR makefile vars
-ifdef GPS_UART_NR
-  $(error GPS_UART_NR is obsolete, please use GPS_PORT instead to define the Uart to use, e.g. <configure name="GPS_PORT" value="UART1"/>)
-endif
-ifdef MODEM_UART_NR
-  $(error MODEM_UART_NR is obsolete, please use MODEM_PORT instead to define the Uart to use, e.g. <configure name="MODEM_PORT" value="UART1"/>)
-endif
 
 $(TARGET).install : warn_conf