diff --git a/changelog.d/+msc4143-versions.feature.md b/changelog.d/+msc4143-versions.feature.md
new file mode 100644
index 000000000..4147cc89a
--- /dev/null
+++ b/changelog.d/+msc4143-versions.feature.md
@@ -0,0 +1 @@
+Advertised MatrixRTC (MSC4143) support in `/_matrix/client/versions`. Contributed by @eleboucher.
diff --git a/src/core/matrix/versions.rs b/src/core/matrix/versions.rs
index e5da78e96..79fbf82dc 100644
--- a/src/core/matrix/versions.rs
+++ b/src/core/matrix/versions.rs
@@ -31,6 +31,8 @@ pub fn versions() -> Vec<String> {
 #[must_use]
 pub fn unstable_features() -> BTreeMap<String, bool> {
 	BTreeMap::from_iter([
+		// MatrixRTC (https://github.com/matrix-org/matrix-spec-proposals/pull/4143)
+		("org.matrix.msc4143".to_owned(), true),
 		// query mutual rooms (https://github.com/matrix-org/matrix-spec-proposals/pull/2666)
 		// Expected for spec v1.19
 		("uk.half-shot.msc2666.query_mutual_rooms".to_owned(), true),