diff --git a/src/plugins/sixrd/sixrd.h b/src/plugins/sixrd/sixrd.h
index 56714c9..f911461 100644
--- a/src/plugins/sixrd/sixrd.h
+++ b/src/plugins/sixrd/sixrd.h
@@ -79,7 +79,7 @@
   u32 sixrd_domain_index;
 } sixrd_trace_t;
 
-sixrd_main_t sixrd_main;
+extern sixrd_main_t sixrd_main;
 
 /*
  * sixrd_get_addr