diff --git a/src/flow-filter.c b/src/flow-filter.c

index cb51aa2..3c1bfea 100644

--- a/src/flow-filter.c

+++ b/src/flow-filter.c

@@ -56,7 +56,7 @@

 int debug;

 int ip_net_only;

-struct acl_list acl_list;

+extern struct acl_list acl_list;

 int yyparse (void);

 void usage(void);