diff --git a/crates/ruma-client-api/CHANGELOG.md b/crates/ruma-client-api/CHANGELOG.md
index 51f601c4..b118d277 100644
--- a/crates/ruma-client-api/CHANGELOG.md
+++ b/crates/ruma-client-api/CHANGELOG.md
@@ -1,5 +1,9 @@
 # [unreleased]
 
+Breaking changes:
+
+* Change inconsistent types in `rooms` and `not_rooms` fields in `RoomEventFilter` structure. Both types now use `RoomId`. 
+
 Improvements:
 
 * Add more endpoints:
diff --git a/crates/ruma-client-api/src/r0/filter.rs b/crates/ruma-client-api/src/r0/filter.rs
index 5f99658c..d4a34db0 100644
--- a/crates/ruma-client-api/src/r0/filter.rs
+++ b/crates/ruma-client-api/src/r0/filter.rs
@@ -63,7 +63,7 @@ pub struct RoomEventFilter<'a> {
     /// If this list is absent then no rooms are excluded. A matching room will be excluded even if
     /// it is listed in the 'rooms' filter.
     #[serde(default, skip_serializing_if = "<[_]>::is_empty")]
-    pub not_rooms: &'a [String],
+    pub not_rooms: &'a [RoomId],
 
     /// The maximum number of events to return.
     #[serde(skip_serializing_if = "Option::is_none")]
diff --git a/crates/ruma-client-api/src/r0/message/get_message_events.rs b/crates/ruma-client-api/src/r0/message/get_message_events.rs
index 08a41d80..2d68052e 100644
--- a/crates/ruma-client-api/src/r0/message/get_message_events.rs
+++ b/crates/ruma-client-api/src/r0/message/get_message_events.rs
@@ -148,7 +148,11 @@ mod tests {
         let filter = RoomEventFilter {
             lazy_load_options: LazyLoadOptions::Enabled { include_redundant_members: true },
             rooms: Some(rooms),
-            not_rooms: &["room".into(), "room2".into(), "room3".into()],
+            not_rooms: &[
+                room_id!("!room:example.org"),
+                room_id!("!room2:example.org"),
+                room_id!("!room3:example.org"),
+            ],
             not_types: &["type".into()],
             ..Default::default()
         };
@@ -172,9 +176,7 @@ mod tests {
              &to=token2\
              &dir=b\
              &limit=0\
-             &filter=%7B%22not_types%22%3A%5B%22type%22%5D%2C%22not_rooms%22%3A%5B%22room%22%2C%22\
-              room2%22%2C%22room3%22%5D%2C%22rooms%22%3A%5B%22%21roomid%3Aexample.org%22%5D%2C%22\
-              lazy_load_members%22%3Atrue%2C%22include_redundant_members%22%3Atrue%7D",
+             &filter=%7B%22not_types%22%3A%5B%22type%22%5D%2C%22not_rooms%22%3A%5B%22%21room%3Aexample.org%22%2C%22%21room2%3Aexample.org%22%2C%22%21room3%3Aexample.org%22%5D%2C%22rooms%22%3A%5B%22%21roomid%3Aexample.org%22%5D%2C%22lazy_load_members%22%3Atrue%2C%22include_redundant_members%22%3Atrue%7D",
             request.uri().query().unwrap()
         );
     }