https://bugs.gentoo.org/709648
--- a/lists.c
+++ b/lists.c
@@ -38,6 +38,8 @@
 
 
 extern int dodo_mode;
+struct pattern_file *pattern_head;
+struct subnet_block *subnet_head;
 
 
 void init_lists(void)
--- a/lists.h
+++ b/lists.h
@@ -45,8 +45,8 @@
 
 
 /* the two chief lists */
-struct subnet_block *subnet_head;
-struct pattern_file *pattern_head;
+extern struct subnet_block *subnet_head;
+extern struct pattern_file *pattern_head;