diff --git a/ext/date/zonetab.h b/ext/date/zonetab.h
index 9d234a5e43..1497eb5f65 100644
--- a/ext/date/zonetab.h
+++ b/ext/date/zonetab.h
@@ -35,7 +35,7 @@ struct zone {
     int name;
     int offset;
 };
-
+static const struct zone *zonetab();
 #line 9 "zonetab.list"
 struct zone;
 /* maximum key range = 434, duplicates = 0 */
diff --git a/ext/date/zonetab.list b/ext/date/zonetab.list
index e4b67ad81e..3a4d121d2e 100644
--- a/ext/date/zonetab.list
+++ b/ext/date/zonetab.list
@@ -3,7 +3,7 @@ struct zone {
     int name;
     int offset;
 };
-
+static const struct zone *zonetab();
 %}
 
 struct zone;