diff --git a/proposals/4449-get-members-filters.md b/proposals/4449-get-members-filters.md
new file mode 100644
index 00000000000..8c9efc75c3f
--- /dev/null
+++ b/proposals/4449-get-members-filters.md
@@ -0,0 +1,50 @@
+# MSC4449: Updated /members filtering
+
+Currently, [`GET /_matrix/client/v3/rooms/{roomId}/members`][s1] only allows filtering up to one
+kind of membership per filter.
+This means clients can only request members who match a specific membership, or do not match a
+specific membership. This proposal aims to make this endpoint more intuitive and useful by allowing
+the filters to match against multiple memberships.
+
+[s1]: https://spec.matrix.org/v1.18/client-server-api/#get_matrixclientv3roomsroomidmembers
+
+## Proposal
+
+Building on the art of [MSC2895](https://github.com/matrix-org/matrix-spec-proposals/pull/2895),
+this proposal will spearhead one of the options proposed.
+
+As it appears to be the least complex change, the `membership` and `not_membership` query parameters
+are updated to allow being provided multiple times, to specify multiple matches. For example,
+specifying `?membership=join&membership=invite` will yield all memberships of kinds `join`, *or*
+`invite`. Specifying `?not_membership=leave&not_membership=ban` will yield all memberships that are
+NOT of kinds `leave` or `ban` (so, at the time of writing, `join`, `invite`, or `knock`).
+
+As part of this change, they are also made *mutually exclusive*. Specifying both `membership` and
+`not_membership` in the same query is explicitly forbidden, and will return `400 / M_INVALID_PARAM`.
+
+## Potential issues
+
+This change re-uses existing parameter names and may confuse older servers if newer clients try to
+request data with the updated filter behaviour. In order to attempt to reduce this collision,
+clients should check for the unstable feature or relevant spec version (if merged) in `/versions`
+before using the updated behaviour.
+
+## Alternatives
+
+As mentioned, [MSC2895](https://github.com/matrix-org/matrix-spec-proposals/pull/2895) provides some
+ideas for further changes to the members endpoint, alongside some other ones.
+
+## Security considerations
+
+None
+
+## Unstable prefix
+
+Implementations should use `uk.timedout.msc4449.membership` and `uk.timedout.msc4449.not_membership`
+as query parameters for the duration of the proposal's unstable period. Servers *SHOULD* advertise
+`uk.timedout.msc4449` in `/_matrix/client/versions` too, so that clients will know they can use the
+new parameters.
+
+## Dependencies
+
+None