diff --git a/b2/Makefile b/b2/Makefile
index 9479ca2..f1cc9f8 100644
--- a/b2/Makefile
+++ b/b2/Makefile
@@ -46,6 +46,12 @@ else
 	DEPEND	= $(DEPEND_quiet)
 endif
 
+MKDEP = $(DEPEND) $(1).c | \
+	sed -e \
+	'/^\(.*:\)\? */{p;s///;s/ *\\\?$$/ /;s/  */:\n/g;H;}' \
+	  -e '$${g;p;}' -e d >$(1).d; \
+	[ "$${PIPESTATUS[*]}" = "0 0" ] || { rm -f $(1).d; exit 1; }
+
 .PHONY:	all clean spotless try
 
 all:		boom
@@ -58,20 +64,18 @@ lex.yy.c:	lang.l y.tab.h
 
 lex.yy.o:	lex.yy.c y.tab.h
 		$(CC) -c $(CFLAGS) $(SLOPPY) lex.yy.c
+		$(call MKDEP, lex.yy)
 
 y.tab.c y.tab.h: lang.y
 		$(YACC) $(YYFLAGS) -d lang.y
 
 y.tab.o:	y.tab.c
 		$(CC) -c $(CFLAGS) $(SLOPPY) y.tab.c
+		$(call MKDEP, y.tab)
 
 %.o:		%.c
 		$(CC) -c $(CFLAGS) $*.c -o $*.o
-		$(DEPEND) $*.c | \
-		  sed -e \
-		    '/^\(.*:\)\? */{p;s///;s/ *\\\?$$/ /;s/  */:\n/g;H;}' \
-		    -e '$${g;p;}' -e d >$*.d; \
-		  [ "$${PIPESTATUS[*]}" = "0 0" ] || { rm -f $*.d; exit 1; }
+		$(call MKDEP, $*)
 
 -include $(OBJS:.o=.d)