diff -Nuar blktrace.orig/Makefile blktrace/Makefile
--- blktrace.orig/Makefile	2008-10-30 07:20:02.000000000 -0700
+++ blktrace/Makefile	2009-04-12 17:54:46.351588795 -0700
@@ -10,13 +10,13 @@
 
 all: $(ALL)
 
-btt/btt:
+btt/btt: $(PROGS)
 	$(MAKE) -C btt
 
-btreplay/btrecord:
+btreplay/btrecord: $(PROGS)
 	$(MAKE) -C btreplay
 
-btreplay/btreplay:
+btreplay/btreplay: $(PROGS)
 	$(MAKE) -C btreplay
 
 %.o: %.c