diff --git a/Makefile b/Makefile
index eeab5d0942..58324688a6 100644
--- a/Makefile
+++ b/Makefile
@@ -104,10 +104,17 @@ GEN_HEADERS = $(MESSAGES_H) $(UBX_PROTOCOL_H) $(MTK_PROTOCOL_H) $(XSENS_PROTOCOL
 
 all: ground_segment ext lpctools
 
-print_build_version:
+_print_building:
 	@echo "------------------------------------------------------------"
 	@echo "Building Paparazzi version" $(shell ./paparazzi_version)
 	@echo "------------------------------------------------------------"
+
+print_build_version:
+	@echo "------------------------------------------------------------"
+	@echo "Last build Paparazzi version" $(shell cat $(PAPARAZZI_HOME)/var/build_version.txt 2> /dev/null || echo UNKNOWN)
+	@echo "------------------------------------------------------------"
+
+_save_build_version:
 	$(Q)test -d $(PAPARAZZI_HOME)/var || mkdir -p $(PAPARAZZI_HOME)/var
 	$(Q)./paparazzi_version > $(PAPARAZZI_HOME)/var/build_version.txt
 
@@ -120,12 +127,12 @@ conf/%.xml :conf/%_example.xml
 	[ -L $@ ] || [ -f $@ ] || cp $< $@
 
 
-ground_segment: print_build_version update_google_version conf libpprz subdirs commands static
+ground_segment: _print_building update_google_version conf libpprz subdirs commands static
 ground_segment.opt: ground_segment cockpit.opt tmtc.opt
 
 static: cockpit tmtc generators sim_static joystick static_h
 
-libpprz:
+libpprz: _save_build_version
 	$(MAKE) -C $(LIB)/ocaml
 
 multimon:
@@ -311,7 +318,7 @@ run_tests:
 test: all replace_current_conf_xml run_tests restore_conf_xml
 
 
-.PHONY: all print_build_version update_google_version dox ground_segment ground_segment.opt \
+.PHONY: all print_build_version _print_building _save_build_version update_google_version dox ground_segment ground_segment.opt \
 subdirs $(SUBDIRS) conf ext libpprz multimon cockpit cockpit.opt tmtc tmtc.opt generators\
 static sim_static lpctools commands \
 clean cleanspaces ab_clean dist_clean distclean dist_clean_irreversible \
diff --git a/Makefile.ac b/Makefile.ac
index d892d049d1..3ee019c66e 100644
--- a/Makefile.ac
+++ b/Makefile.ac
@@ -84,7 +84,8 @@ ifneq ($(words $(GIT_SHA1)),1)
 GIT_SHA1 := "UNKNOWN"
 endif
 GIT_DESC := $(shell ./paparazzi_version)
-BUILD_DESC := $(shell cat $(PAPARAZZI_HOME)/var/build_version.txt)
+BUILD_DESC := $(shell cat $(PAPARAZZI_HOME)/var/build_version.txt 2> /dev/null || echo UNKNOWN)
+# extract only version number in format <major>.<minor>.<patch>
 PPRZ_VER := $(shell echo $(GIT_DESC) | sed 's/[^0-9.]*\([0-9.]*\).*/\1/')
 PPRZ_VER_MAJOR := $(shell echo $(GIT_DESC) | sed 's/v\([0-9]*\).*/\1/')
 PPRZ_VER_MINOR := $(shell echo $(GIT_DESC) | sed 's/v[0-9]*.\([0-9]*\).*/\1/')
@@ -99,10 +100,10 @@ export PPRZ_VER_MAJOR
 export PPRZ_VER_MINOR
 export PPRZ_VER_PATCH
 
-ifneq ($(GIT_DESC),$(BUILD_DESC))
-VERSION_MATCH = "\nWarning: version differ from build version ($(BUILD_DESC))"
-else
+# show warning with print_version if PPRZ_VER (e.g. 5.3.2) is not part of the BUILD_DESC string
 VERSION_MATCH = ""
+ifeq (,$(findstring $(PPRZ_VER),$(BUILD_DESC)))
+VERSION_MATCH = "\nWarning: version differs from build version ($(BUILD_DESC)), you might want to run the toplevel make."
 endif
 
 # "make Q=''" to get full echo