diff --git a/back/methods/postcode/filter.js b/back/methods/postcode/filter.js
index dcf11f80b..9986a16c9 100644
--- a/back/methods/postcode/filter.js
+++ b/back/methods/postcode/filter.js
@@ -50,7 +50,7 @@ module.exports = Self => {
             }
         }) ?? {};
 
-        filter = mergeFilters(ctx.args.filter, {where});
+        filter = mergeFilters(ctx.args?.filter ?? {}, {where});
 
         const stmts = [];
         let stmt;