diff --git a/conf/Makefile b/conf/Makefile
index dae3dd18..1b8bc717 100644
--- a/conf/Makefile
+++ b/conf/Makefile
@@ -23,7 +23,7 @@ keywords.h: $(conf-fragments) $(conf-src)/gen_keywords.m4
 commands.h: $(conf-fragments) $(conf-src)/gen_commands.m4 $(srcdir)/client/cmds.m4
 	$(M4) -P $(conf-src)/gen_commands.m4 $(srcdir)/client/cmds.m4 $(conf-fragments) | sort >commands.h
 
-cf-lex.c: cf-lex.l
+cf-lex.c: cf-lex.l cf-parse-tab.h
 	$(FLEX) $(FLEX_DEBUG) -s -B -8 -ocf-lex.c -Pcf_ cf-lex.l
 
 depend: keywords.h commands.h cf-parse.tab.c cf-lex.c