--- a/Makefile	Wed Jul 06 12:19:30 2011 +0200
+++ b/Makefile	Thu Jul 07 10:49:08 2011 +0200
@@ -42,7 +42,7 @@
 	-rm -f iec2iec iec2c *.o absyntax/*.o
 	echo > Makefile.depend
 # make something everywhere (ie, in all Makefiles that have that target)
-	find . -depth -mindepth 2 -maxdepth 2 -name Makefile | sed 's/Makefile//g' | xargs -I {} make -C{} clean
+	find . -depth -mindepth 2 -maxdepth 2 -name Makefile | sed 's/Makefile//g' | xargs -I {} $(MAKE) -C{} clean
 
 CXXFLAGS += -I.