diff --git a/checkpolicy/Makefile b/checkpolicy/Makefile
index e5fae3df..53a30745 100644
--- a/checkpolicy/Makefile
+++ b/checkpolicy/Makefile
@@ -8,6 +8,7 @@ LIBDIR ?= $(PREFIX)/lib
 INCLUDEDIR ?= $(PREFIX)/include
 TARGETS = checkpolicy checkmodule
 
+LEX = flex
 YACC = bison -y
 
 CFLAGS ?= -g -Wall -Werror -Wshadow -O2 -pipe -fno-strict-aliasing