diff --git a/worf/views/list.py b/worf/views/list.py
index 7c1ce4f..d889a68 100644
--- a/worf/views/list.py
+++ b/worf/views/list.py
@@ -111,7 +111,14 @@ def set_search_lookup_kwargs(self):
             if isinstance(self.bundle[key], list):
                 if not all(isinstance(x, int) for x in self.bundle[key]):
                     self.coerce_array_of_integers(key)  # raises 422 if failure
-                self.lookup_kwargs.update({f"{key}__in": self.bundle[key]})
+                    self.lookup_kwargs.update(
+                        {
+                            f"{key}__in": ",".join(
+                                str(value) for value in self.bundle[key]
+                            )
+                        }
+                    )
+
                 continue
 
             self.validate_bundle(key)