diff --git a/crates/ruma-state-res/src/lib.rs b/crates/ruma-state-res/src/lib.rs
index 89d490aa..23cf475e 100644
--- a/crates/ruma-state-res/src/lib.rs
+++ b/crates/ruma-state-res/src/lib.rs
@@ -1223,7 +1223,7 @@ mod tests {
         let exists = |id: <PduEvent as Event>::Id| ready(ev_map.get(&*id).is_some());
 
         let state_sets = [state_at_bob, state_at_charlie];
-        let auth_chain = state_sets
+        let auth_chain: Vec<_> = state_sets
             .iter()
             .map(|map| store.auth_event_ids(room_id(), map.values().cloned().collect()).unwrap())
             .collect();
@@ -1330,7 +1330,7 @@ mod tests {
 
         let ev_map = &store.0;
         let state_sets = [state_set_a, state_set_b];
-        let auth_chain = state_sets
+        let auth_chain: Vec<_> = state_sets
             .iter()
             .map(|map| store.auth_event_ids(room_id(), map.values().cloned().collect()).unwrap())
             .collect();
diff --git a/crates/ruma-state-res/src/test_utils.rs b/crates/ruma-state-res/src/test_utils.rs
index 5ce7b6cc..e32f6dea 100644
--- a/crates/ruma-state-res/src/test_utils.rs
+++ b/crates/ruma-state-res/src/test_utils.rs
@@ -112,7 +112,7 @@ pub(crate) async fn do_check(
                     .collect::<Vec<_>>()
             );
 
-            let auth_chain_sets = state_sets
+            let auth_chain_sets: Vec<_> = state_sets
                 .iter()
                 .map(|map| {
                     store.auth_event_ids(room_id(), map.values().cloned().collect()).unwrap()
@@ -626,6 +626,7 @@ pub(crate) mod event {
             }
         }
 
+        #[allow(refining_impl_trait)]
         fn prev_events(&self) -> Box<dyn DoubleEndedIterator<Item = &Self::Id> + Send + '_> {
             match &self.rest {
                 Pdu::RoomV1Pdu(ev) => Box::new(ev.prev_events.iter().map(|(id, _)| id)),
@@ -635,6 +636,7 @@ pub(crate) mod event {
             }
         }
 
+        #[allow(refining_impl_trait)]
         fn auth_events(&self) -> Box<dyn DoubleEndedIterator<Item = &Self::Id> + Send + '_> {
             match &self.rest {
                 Pdu::RoomV1Pdu(ev) => Box::new(ev.auth_events.iter().map(|(id, _)| id)),