diff --git a/src/api/client/capabilities.rs b/src/api/client/capabilities.rs
index 3c278426..83e1dc7e 100644
--- a/src/api/client/capabilities.rs
+++ b/src/api/client/capabilities.rs
@@ -7,6 +7,7 @@ use ruma::{
 	},
 	RoomVersionId,
 };
+use serde_json::json;
 
 use crate::{Result, Ruma};
 
@@ -42,6 +43,11 @@ pub(crate) async fn get_capabilities_route(
 		enabled: false,
 	};
 
+	// MSC4133 capability
+	capabilities
+		.set("uk.tcpip.msc4133.profile_fields", json!({"enabled": true}))
+		.expect("this is valid JSON we created");
+
 	Ok(get_capabilities::v3::Response {
 		capabilities,
 	})
diff --git a/src/api/client/unversioned.rs b/src/api/client/unversioned.rs
index 76574949..d714fda5 100644
--- a/src/api/client/unversioned.rs
+++ b/src/api/client/unversioned.rs
@@ -55,6 +55,8 @@ pub(crate) async fn get_supported_versions_route(
 			("org.matrix.msc3575".to_owned(), true), /* sliding sync (https://github.com/matrix-org/matrix-spec-proposals/pull/3575/files#r1588877046) */
 			("org.matrix.msc3916.stable".to_owned(), true), /* authenticated media (https://github.com/matrix-org/matrix-spec-proposals/pull/3916) */
 			("org.matrix.msc4180".to_owned(), true), /* stable flag for 3916 (https://github.com/matrix-org/matrix-spec-proposals/pull/4180) */
+			("uk.tcpip.msc4133".to_owned(), true), /* Extending User Profile API with Key:Value Pairs (https://github.com/matrix-org/matrix-spec-proposals/pull/4133) */
+			("us.cloke.msc4175".to_owned(), true), /* Profile field for user time zone (https://github.com/matrix-org/matrix-spec-proposals/pull/4175) */
 		]),
 	};