diff --git a/DEPENDS b/DEPENDS
index 0e1de719..48df53aa 100644
--- a/DEPENDS
+++ b/DEPENDS
@@ -6,6 +6,7 @@ In that case, please try using the versions mentioned below until a fix is provi
  * libxcb-1.1.93 (2008-12-11)
  * xcb-util-0.3.3 (2009-01-31)
  * libev
+ * flex and bison
  * asciidoc >= 8.3.0 for docs/hacking-howto
  * asciidoc, xmlto, docbook-xml for man/i3.man
  * Xlib, the one that comes with your X-Server
@@ -19,6 +20,8 @@ http://xcb.freedesktop.org/dist/xcb-proto-1.5.tar.bz2
 http://xcb.freedesktop.org/dist/libxcb-1.1.93.tar.bz2
 http://xcb.freedesktop.org/dist/xcb-util-0.3.5.tar.bz2
 http://libev.schmorp.de/
+http://flex.sourceforge.net/
+http://www.gnu.org/software/bison/
 
 http://i3.zekjur.net/i3lock/
 http://tools.suckless.org/dmenu
diff --git a/Makefile b/Makefile
index e4a04bb5..6e32ac4a 100644
--- a/Makefile
+++ b/Makefile
@@ -24,12 +24,12 @@ all: src/cfgparse.y.o src/cfgparse.yy.o ${FILES}
 
 src/cfgparse.yy.o: src/cfgparse.l
 	echo "LEX $<"
-	lex -i -o $(@:.o=.c) $<
+	flex -i -o$(@:.o=.c) $<
 	$(CC) $(CFLAGS) -c -o $@ $(@:.o=.c)
 
 src/cfgparse.y.o: src/cfgparse.y
 	echo "YACC $<"
-	yacc --debug --verbose -b $(basename $< .y) -d $<
+	bison --debug --verbose -b $(basename $< .y) -d $<
 	$(CC) $(CFLAGS) -c -o $@ $(<:.y=.tab.c)
 
 install: all