diff --git a/crates/ruma-client-api/src/r0/directory.rs b/crates/ruma-client-api/src/r0/directory.rs
index fb78e004..8bbd08e1 100644
--- a/crates/ruma-client-api/src/r0/directory.rs
+++ b/crates/ruma-client-api/src/r0/directory.rs
@@ -54,7 +54,7 @@ pub struct PublicRoomsChunk {
         feature = "compat",
         serde(default, deserialize_with = "ruma_serde::empty_string_as_none")
     )]
-    pub avatar_url: Option<MxcUri>,
+    pub avatar_url: Option<Box<MxcUri>>,
 
     /// The joining rule for the room.
     #[cfg(feature = "unstable-pre-spec")]
diff --git a/crates/ruma-client-api/src/r0/media/create_content.rs b/crates/ruma-client-api/src/r0/media/create_content.rs
index 8bafcc2b..b93d52c7 100644
--- a/crates/ruma-client-api/src/r0/media/create_content.rs
+++ b/crates/ruma-client-api/src/r0/media/create_content.rs
@@ -39,7 +39,7 @@ ruma_api! {
 
     response: {
         /// The MXC URI for the uploaded content.
-        pub content_uri: MxcUri,
+        pub content_uri: Box<MxcUri>,
 
         /// The [BlurHash](https://blurha.sh) for the uploaded content.
         ///
@@ -68,7 +68,7 @@ impl<'a> Request<'a> {
 
 impl Response {
     /// Creates a new `Response` with the given MXC URI.
-    pub fn new(content_uri: MxcUri) -> Self {
+    pub fn new(content_uri: Box<MxcUri>) -> Self {
         Self {
             content_uri,
             #[cfg(feature = "unstable-pre-spec")]
diff --git a/crates/ruma-client-api/src/r0/membership/joined_members.rs b/crates/ruma-client-api/src/r0/membership/joined_members.rs
index dbf97524..fb4a424a 100644
--- a/crates/ruma-client-api/src/r0/membership/joined_members.rs
+++ b/crates/ruma-client-api/src/r0/membership/joined_members.rs
@@ -62,7 +62,7 @@ pub struct RoomMember {
         feature = "compat",
         serde(default, deserialize_with = "ruma_serde::empty_string_as_none")
     )]
-    pub avatar_url: Option<MxcUri>,
+    pub avatar_url: Option<Box<MxcUri>>,
 }
 
 impl RoomMember {
@@ -89,7 +89,7 @@ mod test {
                 display_name: Some(display_name),
                 avatar_url: Some(avatar_url),
             } if display_name == "alice"
-                && avatar_url.to_string() == "mxc://localhost/wefuiwegh8742w"
+                && avatar_url == "mxc://localhost/wefuiwegh8742w"
         );
 
         #[cfg(feature = "compat")]
diff --git a/crates/ruma-client-api/src/r0/profile/get_avatar_url.rs b/crates/ruma-client-api/src/r0/profile/get_avatar_url.rs
index 17104e64..bcd6e1f5 100644
--- a/crates/ruma-client-api/src/r0/profile/get_avatar_url.rs
+++ b/crates/ruma-client-api/src/r0/profile/get_avatar_url.rs
@@ -30,7 +30,7 @@ ruma_api! {
             feature = "compat",
             serde(default, deserialize_with = "ruma_serde::empty_string_as_none")
         )]
-        pub avatar_url: Option<MxcUri>,
+        pub avatar_url: Option<Box<MxcUri>>,
 
         /// The [BlurHash](https://blurha.sh) for the avatar pointed to by `avatar_url`.
         ///
@@ -53,7 +53,7 @@ impl<'a> Request<'a> {
 
 impl Response {
     /// Creates a new `Response` with the given avatar URL.
-    pub fn new(avatar_url: Option<MxcUri>) -> Self {
+    pub fn new(avatar_url: Option<Box<MxcUri>>) -> Self {
         Self {
             avatar_url,
             #[cfg(feature = "unstable-pre-spec")]
diff --git a/crates/ruma-client-api/src/r0/profile/get_profile.rs b/crates/ruma-client-api/src/r0/profile/get_profile.rs
index fbab27ff..58ae9b5a 100644
--- a/crates/ruma-client-api/src/r0/profile/get_profile.rs
+++ b/crates/ruma-client-api/src/r0/profile/get_profile.rs
@@ -30,7 +30,7 @@ ruma_api! {
             feature = "compat",
             serde(default, deserialize_with = "ruma_serde::empty_string_as_none")
         )]
-        pub avatar_url: Option<MxcUri>,
+        pub avatar_url: Option<Box<MxcUri>>,
 
         /// The user's display name, if set.
         #[serde(skip_serializing_if = "Option::is_none")]
@@ -57,7 +57,7 @@ impl<'a> Request<'a> {
 
 impl Response {
     /// Creates a new `Response` with the given avatar URL and display name.
-    pub fn new(avatar_url: Option<MxcUri>, displayname: Option<String>) -> Self {
+    pub fn new(avatar_url: Option<Box<MxcUri>>, displayname: Option<String>) -> Self {
         Self {
             avatar_url,
             displayname,
diff --git a/crates/ruma-client-api/src/r0/search/search_events.rs b/crates/ruma-client-api/src/r0/search/search_events.rs
index be4afb61..d6c675ae 100644
--- a/crates/ruma-client-api/src/r0/search/search_events.rs
+++ b/crates/ruma-client-api/src/r0/search/search_events.rs
@@ -474,7 +474,7 @@ pub struct UserProfile {
         feature = "compat",
         serde(default, deserialize_with = "ruma_serde::empty_string_as_none")
     )]
-    pub avatar_url: Option<MxcUri>,
+    pub avatar_url: Option<Box<MxcUri>>,
 
     /// The user's display name, if set.
     #[serde(skip_serializing_if = "Option::is_none")]
diff --git a/crates/ruma-client-api/src/r0/session/get_login_types.rs b/crates/ruma-client-api/src/r0/session/get_login_types.rs
index 1a77c6dd..020b45bb 100644
--- a/crates/ruma-client-api/src/r0/session/get_login_types.rs
+++ b/crates/ruma-client-api/src/r0/session/get_login_types.rs
@@ -178,7 +178,7 @@ pub struct IdentityProvider {
     name: String,
 
     /// The icon for the provider.
-    icon: Option<MxcUri>,
+    icon: Option<Box<MxcUri>>,
 
     /// The brand identifier for the provider.
     brand: Option<IdentityProviderBrand>,
@@ -337,7 +337,7 @@ mod tests {
                 brand: Some(IdentityProviderBrand::GitLab),
             }) if id == "oidc-gitlab"
                 && name == "GitLab"
-                && icon.to_string() == "mxc://localhost/gitlab-icon"
+                && icon == "mxc://localhost/gitlab-icon"
         );
     }
 
diff --git a/crates/ruma-client-api/src/r0/user_directory/search_users.rs b/crates/ruma-client-api/src/r0/user_directory/search_users.rs
index 86ae7bee..4cdb0a2b 100644
--- a/crates/ruma-client-api/src/r0/user_directory/search_users.rs
+++ b/crates/ruma-client-api/src/r0/user_directory/search_users.rs
@@ -87,7 +87,7 @@ pub struct User {
         feature = "compat",
         serde(default, deserialize_with = "ruma_serde::empty_string_as_none")
     )]
-    pub avatar_url: Option<MxcUri>,
+    pub avatar_url: Option<Box<MxcUri>>,
 }
 
 impl User {
diff --git a/crates/ruma-common/src/directory.rs b/crates/ruma-common/src/directory.rs
index 3ec2934c..1b875910 100644
--- a/crates/ruma-common/src/directory.rs
+++ b/crates/ruma-common/src/directory.rs
@@ -58,7 +58,7 @@ pub struct PublicRoomsChunk {
         feature = "compat",
         serde(default, deserialize_with = "ruma_serde::empty_string_as_none")
     )]
-    pub avatar_url: Option<MxcUri>,
+    pub avatar_url: Option<Box<MxcUri>>,
 }
 
 /// Initial set of mandatory fields of `PublicRoomsChunk`.
diff --git a/crates/ruma-events/src/enums.rs b/crates/ruma-events/src/enums.rs
index 4389e951..758ab706 100644
--- a/crates/ruma-events/src/enums.rs
+++ b/crates/ruma-events/src/enums.rs
@@ -57,7 +57,6 @@ event_enum! {
         "m.sticker",
     }
 
-
     /// Any state event.
     enum State {
         "m.policy.rule.room",
diff --git a/crates/ruma-events/src/presence.rs b/crates/ruma-events/src/presence.rs
index 6415253e..d4ca826b 100644
--- a/crates/ruma-events/src/presence.rs
+++ b/crates/ruma-events/src/presence.rs
@@ -37,7 +37,7 @@ pub struct PresenceEventContent {
         feature = "compat",
         serde(default, deserialize_with = "ruma_serde::empty_string_as_none")
     )]
-    pub avatar_url: Option<MxcUri>,
+    pub avatar_url: Option<Box<MxcUri>>,
 
     /// Whether or not the user is currently active.
     #[serde(skip_serializing_if = "Option::is_none")]
@@ -92,7 +92,7 @@ mod tests {
     fn serialization() {
         let event = PresenceEvent {
             content: PresenceEventContent {
-                avatar_url: Some(mxc_uri!("mxc://localhost/wefuiwegh8742w")),
+                avatar_url: Some(mxc_uri!("mxc://localhost/wefuiwegh8742w").to_owned()),
                 currently_active: Some(false),
                 displayname: None,
                 last_active_ago: Some(uint!(2_478_593)),
@@ -143,7 +143,7 @@ mod tests {
                     status_msg: Some(status_msg),
                 },
                 sender,
-            } if avatar_url.to_string() == "mxc://localhost/wefuiwegh8742w"
+            } if avatar_url == "mxc://localhost/wefuiwegh8742w"
                 && status_msg == "Making cupcakes"
                 && sender == "@example:localhost"
                 && last_active_ago == uint!(2_478_593)
diff --git a/crates/ruma-events/src/room.rs b/crates/ruma-events/src/room.rs
index 86385795..acbc4a6b 100644
--- a/crates/ruma-events/src/room.rs
+++ b/crates/ruma-events/src/room.rs
@@ -56,7 +56,7 @@ pub struct ImageInfo {
     ///
     /// Only present if the thumbnail is unencrypted.
     #[serde(skip_serializing_if = "Option::is_none")]
-    pub thumbnail_url: Option<MxcUri>,
+    pub thumbnail_url: Option<Box<MxcUri>>,
 
     /// Information on the encrypted thumbnail image.
     ///
@@ -116,7 +116,7 @@ impl ThumbnailInfo {
 #[cfg_attr(not(feature = "unstable-exhaustive-types"), non_exhaustive)]
 pub struct EncryptedFile {
     /// The URL to the file.
-    pub url: MxcUri,
+    pub url: Box<MxcUri>,
 
     /// A [JSON Web Key](https://tools.ietf.org/html/rfc7517#appendix-A.3) object.
     pub key: JsonWebKey,
@@ -143,7 +143,7 @@ pub struct EncryptedFile {
 #[allow(clippy::exhaustive_structs)]
 pub struct EncryptedFileInit {
     /// The URL to the file.
-    pub url: MxcUri,
+    pub url: Box<MxcUri>,
 
     /// A [JSON Web Key](https://tools.ietf.org/html/rfc7517#appendix-A.3) object.
     pub key: JsonWebKey,
diff --git a/crates/ruma-events/src/room/avatar.rs b/crates/ruma-events/src/room/avatar.rs
index 1a86fae3..49cc2694 100644
--- a/crates/ruma-events/src/room/avatar.rs
+++ b/crates/ruma-events/src/room/avatar.rs
@@ -25,13 +25,13 @@ pub struct RoomAvatarEventContent {
     ///
     /// With the `unstable-pre-spec` feature, this field is optional.
     #[cfg(not(feature = "unstable-pre-spec"))]
-    pub url: MxcUri,
+    pub url: Box<MxcUri>,
 
     /// URL of the avatar image.
     ///
     /// Without the `unstable-pre-spec` feature, this field is not optional.
     #[cfg(feature = "unstable-pre-spec")]
-    pub url: Option<MxcUri>,
+    pub url: Option<Box<MxcUri>>,
 }
 
 impl RoomAvatarEventContent {
@@ -39,7 +39,7 @@ impl RoomAvatarEventContent {
     ///
     /// With the `unstable-pre-spec` feature, this method takes no parameters.
     #[cfg(not(feature = "unstable-pre-spec"))]
-    pub fn new(url: MxcUri) -> Self {
+    pub fn new(url: Box<MxcUri>) -> Self {
         Self { info: None, url }
     }
 
@@ -78,7 +78,7 @@ pub struct ImageInfo {
 
     /// The URL to the thumbnail of the image.
     #[serde(skip_serializing_if = "Option::is_none")]
-    pub thumbnail_url: Option<MxcUri>,
+    pub thumbnail_url: Option<Box<MxcUri>>,
 
     /// The [BlurHash](https://blurha.sh) for this image.
     ///
diff --git a/crates/ruma-events/src/room/member.rs b/crates/ruma-events/src/room/member.rs
index 99da7625..2c10fad5 100644
--- a/crates/ruma-events/src/room/member.rs
+++ b/crates/ruma-events/src/room/member.rs
@@ -49,7 +49,7 @@ pub struct RoomMemberEventContent {
         feature = "compat",
         serde(default, deserialize_with = "ruma_serde::empty_string_as_none")
     )]
-    pub avatar_url: Option<MxcUri>,
+    pub avatar_url: Option<Box<MxcUri>>,
 
     /// The display name for this user, if any.
     ///
@@ -489,7 +489,7 @@ mod tests {
                 state_key,
                 unsigned,
                 prev_content: None,
-            } if avatar_url.to_string() == "mxc://example.org/SEsfnsuifSDFSSEF"
+            } if avatar_url == "mxc://example.org/SEsfnsuifSDFSSEF"
                 && displayname == "Alice Margatroid"
                 && third_party_displayname == "alice"
                 && mxid == "@alice:example.org"
@@ -574,7 +574,7 @@ mod tests {
                 && sender == "@alice:example.org"
                 && state_key == "@alice:example.org"
                 && unsigned.is_empty()
-                && avatar_url.to_string() == "mxc://example.org/SEsfnsuifSDFSSEF"
+                && avatar_url == "mxc://example.org/SEsfnsuifSDFSSEF"
                 && displayname == "Alice Margatroid"
                 && third_party_displayname == "alice"
                 && mxid == "@alice:example.org"
diff --git a/crates/ruma-events/src/room/message.rs b/crates/ruma-events/src/room/message.rs
index 45bb9103..59bdfad3 100644
--- a/crates/ruma-events/src/room/message.rs
+++ b/crates/ruma-events/src/room/message.rs
@@ -403,7 +403,7 @@ pub struct AudioMessageEventContent {
     ///
     /// Required if the file is unencrypted.
     #[serde(skip_serializing_if = "Option::is_none")]
-    pub url: Option<MxcUri>,
+    pub url: Option<Box<MxcUri>>,
 
     /// Information on the encrypted audio clip.
     ///
@@ -419,7 +419,7 @@ pub struct AudioMessageEventContent {
 impl AudioMessageEventContent {
     /// Creates a new non-encrypted `RoomAudioMessageEventContent` with the given body, url and
     /// optional extra info.
-    pub fn plain(body: String, url: MxcUri, info: Option<Box<AudioInfo>>) -> Self {
+    pub fn plain(body: String, url: Box<MxcUri>, info: Option<Box<AudioInfo>>) -> Self {
         Self { body, url: Some(url), info, file: None }
     }
 
@@ -504,7 +504,7 @@ pub struct FileMessageEventContent {
 
     /// The URL to the file.
     #[serde(skip_serializing_if = "Option::is_none")]
-    pub url: Option<MxcUri>,
+    pub url: Option<Box<MxcUri>>,
 
     /// Information on the encrypted file.
     ///
@@ -520,7 +520,7 @@ pub struct FileMessageEventContent {
 impl FileMessageEventContent {
     /// Creates a new non-encrypted `RoomFileMessageEventContent` with the given body, url and
     /// optional extra info.
-    pub fn plain(body: String, url: MxcUri, info: Option<Box<FileInfo>>) -> Self {
+    pub fn plain(body: String, url: Box<MxcUri>, info: Option<Box<FileInfo>>) -> Self {
         Self { body, filename: None, url: Some(url), info, file: None }
     }
 
@@ -551,7 +551,7 @@ pub struct FileInfo {
     ///
     /// Only present if the thumbnail is unencrypted.
     #[serde(skip_serializing_if = "Option::is_none")]
-    pub thumbnail_url: Option<MxcUri>,
+    pub thumbnail_url: Option<Box<MxcUri>>,
 
     /// Information on the encrypted thumbnail file.
     ///
@@ -580,7 +580,7 @@ pub struct ImageMessageEventContent {
 
     /// The URL to the image.
     #[serde(skip_serializing_if = "Option::is_none")]
-    pub url: Option<MxcUri>,
+    pub url: Option<Box<MxcUri>>,
 
     /// Information on the encrypted image.
     ///
@@ -596,7 +596,7 @@ pub struct ImageMessageEventContent {
 impl ImageMessageEventContent {
     /// Creates a new non-encrypted `RoomImageMessageEventContent` with the given body, url and
     /// optional extra info.
-    pub fn plain(body: String, url: MxcUri, info: Option<Box<ImageInfo>>) -> Self {
+    pub fn plain(body: String, url: Box<MxcUri>, info: Option<Box<ImageInfo>>) -> Self {
         Self { body, url: Some(url), info, file: None }
     }
 
@@ -639,7 +639,7 @@ pub struct LocationInfo {
     ///
     /// Only present if the thumbnail is unencrypted.
     #[serde(skip_serializing_if = "Option::is_none")]
-    pub thumbnail_url: Option<MxcUri>,
+    pub thumbnail_url: Option<Box<MxcUri>>,
 
     /// Information on an encrypted thumbnail of the location being represented.
     ///
@@ -871,7 +871,7 @@ pub struct VideoMessageEventContent {
 
     /// The URL to the video clip.
     #[serde(skip_serializing_if = "Option::is_none")]
-    pub url: Option<MxcUri>,
+    pub url: Option<Box<MxcUri>>,
 
     /// Information on the encrypted video clip.
     ///
@@ -887,7 +887,7 @@ pub struct VideoMessageEventContent {
 impl VideoMessageEventContent {
     /// Creates a new non-encrypted `RoomVideoMessageEventContent` with the given body, url and
     /// optional extra info.
-    pub fn plain(body: String, url: MxcUri, info: Option<Box<VideoInfo>>) -> Self {
+    pub fn plain(body: String, url: Box<MxcUri>, info: Option<Box<VideoInfo>>) -> Self {
         Self { body, url: Some(url), info, file: None }
     }
 
@@ -930,7 +930,7 @@ pub struct VideoInfo {
     ///
     /// Only present if the thumbnail is unencrypted.
     #[serde(skip_serializing_if = "Option::is_none")]
-    pub thumbnail_url: Option<MxcUri>,
+    pub thumbnail_url: Option<Box<MxcUri>>,
 
     /// Information on the encrypted thumbnail file.
     ///
diff --git a/crates/ruma-events/src/sticker.rs b/crates/ruma-events/src/sticker.rs
index b4f3fb13..ce340fec 100644
--- a/crates/ruma-events/src/sticker.rs
+++ b/crates/ruma-events/src/sticker.rs
@@ -23,12 +23,12 @@ pub struct StickerEventContent {
     pub info: ImageInfo,
 
     /// The URL to the sticker image.
-    pub url: MxcUri,
+    pub url: Box<MxcUri>,
 }
 
 impl StickerEventContent {
     /// Creates a new `StickerEventContent` with the given body, image info and URL.
-    pub fn new(body: String, info: ImageInfo, url: MxcUri) -> Self {
+    pub fn new(body: String, info: ImageInfo, url: Box<MxcUri>) -> Self {
         Self { body, info, url }
     }
 }
diff --git a/crates/ruma-events/tests/event_enums.rs b/crates/ruma-events/tests/event_enums.rs
index a992e318..19db9223 100644
--- a/crates/ruma-events/tests/event_enums.rs
+++ b/crates/ruma-events/tests/event_enums.rs
@@ -82,9 +82,9 @@ fn serialize_message_event() {
                     mimetype: Some("image/png".into()),
                     size: UInt::new(82595),
                 }))),
-                thumbnail_url: Some(mxc_uri!("mxc://matrix.org/mnrsnsRRS787TSts")),
+                thumbnail_url: Some(mxc_uri!("mxc://matrix.org/mnrsnsRRS787TSts").to_owned()),
             }),
-            mxc_uri!("mxc://matrix.org/arsrns98rsRSR"),
+            mxc_uri!("mxc://matrix.org/arsrns98rsRSR").to_owned(),
         ),
         event_id: event_id!("$h29iv0s8:example.com").to_owned(),
         origin_server_ts: MilliSecondsSinceUnixEpoch(uint!(1)),
diff --git a/crates/ruma-events/tests/message_event.rs b/crates/ruma-events/tests/message_event.rs
index 45b82489..1aad80bd 100644
--- a/crates/ruma-events/tests/message_event.rs
+++ b/crates/ruma-events/tests/message_event.rs
@@ -28,9 +28,9 @@ fn message_serialize_sticker() {
                     mimetype: Some("image/png".into()),
                     size: UInt::new(82595),
                 }))),
-                thumbnail_url: Some(mxc_uri!("mxc://matrix.org/irsns989Rrsn")),
+                thumbnail_url: Some(mxc_uri!("mxc://matrix.org/irsns989Rrsn").to_owned()),
             }),
-            mxc_uri!("mxc://matrix.org/rnsldl8srs98IRrs"),
+            mxc_uri!("mxc://matrix.org/rnsldl8srs98IRrs").to_owned(),
         ),
         event_id: event_id!("$h29iv0s8:example.com").to_owned(),
         origin_server_ts: MilliSecondsSinceUnixEpoch(uint!(1)),
@@ -203,7 +203,7 @@ fn deserialize_message_sticker() {
             && width == UInt::new(1011)
             && mimetype == "image/png"
             && size == UInt::new(84242)
-            && thumbnail_url.to_string() == "mxc://matrix.org/irnsNRS2879"
+            && thumbnail_url == "mxc://matrix.org/irnsNRS2879"
             && matches!(
                 thumbnail_info.as_ref(),
                 ThumbnailInfo {
@@ -217,7 +217,7 @@ fn deserialize_message_sticker() {
                     && *thumb_mimetype == Some("image/png".into())
                     && *thumb_size == UInt::new(82595)
             )
-            && url.to_string() == "mxc://matrix.org/jxPXTKpyydzdHJkdFNZjTZrD"
+            && url == "mxc://matrix.org/jxPXTKpyydzdHJkdFNZjTZrD"
             && unsigned.is_empty()
     );
 }
diff --git a/crates/ruma-events/tests/room_message.rs b/crates/ruma-events/tests/room_message.rs
index df912c29..d625a6d9 100644
--- a/crates/ruma-events/tests/room_message.rs
+++ b/crates/ruma-events/tests/room_message.rs
@@ -37,7 +37,7 @@ fn serialization() {
     let ev = RoomMessageEvent {
         content: RoomMessageEventContent::new(MessageType::Audio(AudioMessageEventContent::plain(
             "test".into(),
-            mxc_uri!("mxc://example.org/ffed755USFFxlgbQYZGtryd"),
+            mxc_uri!("mxc://example.org/ffed755USFFxlgbQYZGtryd").to_owned(),
             None,
         ))),
         event_id: event_id!("$143273582443PhrSn:example.org").to_owned(),
@@ -69,7 +69,7 @@ fn content_serialization() {
     let message_event_content =
         RoomMessageEventContent::new(MessageType::Audio(AudioMessageEventContent::plain(
             "test".into(),
-            mxc_uri!("mxc://example.org/ffed755USFFxlgbQYZGtryd"),
+            mxc_uri!("mxc://example.org/ffed755USFFxlgbQYZGtryd").to_owned(),
             None,
         )));
 
@@ -380,7 +380,7 @@ fn content_deserialization() {
                 ..
             }),
             ..
-        } if body == "test" && url.to_string() == "mxc://example.org/ffed755USFFxlgbQYZGtryd"
+        } if body == "test" && url == "mxc://example.org/ffed755USFFxlgbQYZGtryd"
     );
 }
 
diff --git a/crates/ruma-events/tests/state_event.rs b/crates/ruma-events/tests/state_event.rs
index b0667eb0..6efea980 100644
--- a/crates/ruma-events/tests/state_event.rs
+++ b/crates/ruma-events/tests/state_event.rs
@@ -150,6 +150,7 @@ fn deserialize_aliases_sync_with_room_id() {
 }
 
 #[test]
+#[allow(clippy::cmp_owned)] // seems buggy
 fn deserialize_avatar_without_prev_content() {
     let json_data = json!({
         "content": {
@@ -176,7 +177,7 @@ fn deserialize_avatar_without_prev_content() {
         "type": "m.room.avatar"
     });
 
-    let expected_url = "mxc://matrix.org/rnsldl8srs98IRrs".into();
+    let expected_url = mxc_uri!("mxc://matrix.org/rnsldl8srs98IRrs").to_owned();
 
     #[cfg(feature = "unstable-pre-spec")]
     let expected_url = Some(expected_url);
@@ -227,7 +228,7 @@ fn deserialize_avatar_without_prev_content() {
                             && *thumb_height == UInt::new(334)
                             && *thumb_mimetype == Some("image/png".into())
                             && *thumb_size == UInt::new(82595)
-                            && *thumbnail_url == mxc_uri!("mxc://matrix.org/98irRSS23srs")
+                            && thumbnail_url == mxc_uri!("mxc://matrix.org/98irRSS23srs")
                     )
             )
             && url == expected_url
diff --git a/crates/ruma-events/tests/stripped.rs b/crates/ruma-events/tests/stripped.rs
index e19f560f..c7c5de07 100644
--- a/crates/ruma-events/tests/stripped.rs
+++ b/crates/ruma-events/tests/stripped.rs
@@ -120,7 +120,7 @@ fn deserialize_stripped_state_events() {
             let expected_url = mxc_uri!("mxc://example.com/iMag3");
 
             #[cfg(feature = "unstable-pre-spec")]
-            let expected_url = Some(expected_url);
+            let expected_url = Some(expected_url.to_owned());
 
             assert_eq!(image_info.height.unwrap(), uint!(128));
             assert_eq!(image_info.width.unwrap(), uint!(128));
diff --git a/crates/ruma-federation-api/src/query/get_profile_information/v1.rs b/crates/ruma-federation-api/src/query/get_profile_information/v1.rs
index 6c56c40d..91d1f048 100644
--- a/crates/ruma-federation-api/src/query/get_profile_information/v1.rs
+++ b/crates/ruma-federation-api/src/query/get_profile_information/v1.rs
@@ -40,7 +40,7 @@ ruma_api! {
             feature = "compat",
             serde(default, deserialize_with = "ruma_serde::empty_string_as_none")
         )]
-        pub avatar_url: Option<MxcUri>,
+        pub avatar_url: Option<Box<MxcUri>>,
 
         /// The [BlurHash](https://blurha.sh) for the avatar pointed to by `avatar_url`.
         ///
diff --git a/crates/ruma-identifiers-macros/src/lib.rs b/crates/ruma-identifiers-macros/src/lib.rs
index 85bd4608..467e9ec3 100644
--- a/crates/ruma-identifiers-macros/src/lib.rs
+++ b/crates/ruma-identifiers-macros/src/lib.rs
@@ -117,9 +117,7 @@ pub fn mxc_uri(input: TokenStream) -> TokenStream {
     assert!(mxc_uri::validate(&id.value()).is_ok(), "Invalid mxc://");
 
     let output = quote! {
-        <#dollar_crate::MxcUri as ::std::convert::TryFrom<&str>>::try_from(
-            #id,
-        ).unwrap()
+        <&#dollar_crate::MxcUri as ::std::convert::From<&str>>::from(#id)
     };
 
     output.into()
diff --git a/crates/ruma-identifiers/src/mxc_uri.rs b/crates/ruma-identifiers/src/mxc_uri.rs
index f286ff13..ff1d251e 100644
--- a/crates/ruma-identifiers/src/mxc_uri.rs
+++ b/crates/ruma-identifiers/src/mxc_uri.rs
@@ -2,21 +2,22 @@
 //!
 //! [MXC URI]: https://matrix.org/docs/spec/client_server/r0.6.1#mxc-uri
 
-use std::{convert::TryInto, fmt, num::NonZeroU8};
+use std::{convert::TryInto, num::NonZeroU8};
 
 use ruma_identifiers_validation::{error::MxcUriError, mxc_uri::validate};
 
 use crate::ServerName;
 
-type Result<T> = std::result::Result<T, MxcUriError>;
+type Result<T, E = MxcUriError> = std::result::Result<T, E>;
 
 /// A URI that should be a Matrix-spec compliant [MXC URI].
 ///
 /// [MXC URI]: https://matrix.org/docs/spec/client_server/r0.6.1#mxc-uri
-#[derive(Clone, PartialEq, Eq, PartialOrd, Ord, Hash)]
-pub struct MxcUri {
-    full_uri: Box<str>,
-}
+
+#[repr(transparent)]
+pub struct MxcUri(str);
+
+opaque_identifier!(MxcUri);
 
 impl MxcUri {
     /// If this is a valid MXC URI, returns the media ID.
@@ -34,8 +35,8 @@ impl MxcUri {
     pub fn parts(&self) -> Result<(&ServerName, &str)> {
         self.extract_slash_idx().map(|idx| {
             (
-                self.full_uri[6..idx.get() as usize].try_into().unwrap(),
-                &self.full_uri[idx.get() as usize + 1..],
+                self.as_str()[6..idx.get() as usize].try_into().unwrap(),
+                &self.as_str()[idx.get() as usize + 1..],
             )
         })
     }
@@ -51,12 +52,6 @@ impl MxcUri {
         self.validate().is_ok()
     }
 
-    /// Create a string slice from this MXC URI.
-    #[inline(always)]
-    pub fn as_str(&self) -> &str {
-        &self.full_uri
-    }
-
     // convenience method for calling validate(self)
     #[inline(always)]
     fn extract_slash_idx(&self) -> Result<NonZeroU8> {
@@ -64,57 +59,6 @@ impl MxcUri {
     }
 }
 
-impl fmt::Debug for MxcUri {
-    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        self.full_uri.fmt(f)
-    }
-}
-
-impl fmt::Display for MxcUri {
-    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        self.full_uri.fmt(f)
-    }
-}
-
-fn from<S>(uri: S) -> MxcUri
-where
-    S: AsRef<str> + Into<Box<str>>,
-{
-    MxcUri { full_uri: uri.into() }
-}
-
-impl From<&str> for MxcUri {
-    fn from(s: &str) -> Self {
-        from(s)
-    }
-}
-
-impl From<String> for MxcUri {
-    fn from(s: String) -> Self {
-        from(s)
-    }
-}
-
-#[cfg(feature = "serde")]
-impl<'de> serde::Deserialize<'de> for MxcUri {
-    fn deserialize<D>(deserializer: D) -> std::result::Result<Self, D::Error>
-    where
-        D: serde::Deserializer<'de>,
-    {
-        String::deserialize(deserializer).map(Into::into)
-    }
-}
-
-#[cfg(feature = "serde")]
-impl serde::Serialize for MxcUri {
-    fn serialize<S>(&self, serializer: S) -> std::result::Result<S::Ok, S::Error>
-    where
-        S: serde::Serializer,
-    {
-        serializer.serialize_str(&self.to_string())
-    }
-}
-
 #[cfg(test)]
 mod tests {
     use std::convert::TryInto;
@@ -125,7 +69,7 @@ mod tests {
 
     #[test]
     fn parse_mxc_uri() {
-        let mxc = MxcUri::from("mxc://127.0.0.1/asd32asdfasdsd");
+        let mxc = Box::<MxcUri>::from("mxc://127.0.0.1/asd32asdfasdsd");
 
         assert!(mxc.is_valid());
         assert_eq!(
@@ -136,7 +80,7 @@ mod tests {
 
     #[test]
     fn parse_mxc_uri_without_media_id() {
-        let mxc = MxcUri::from("mxc://127.0.0.1");
+        let mxc = Box::<MxcUri>::from("mxc://127.0.0.1");
 
         assert!(!mxc.is_valid());
         assert_eq!(mxc.parts(), Err(MxcUriError::MissingSlash));
@@ -144,14 +88,14 @@ mod tests {
 
     #[test]
     fn parse_mxc_uri_without_protocol() {
-        assert!(!MxcUri::from("127.0.0.1/asd32asdfasdsd").is_valid());
+        assert!(!Box::<MxcUri>::from("127.0.0.1/asd32asdfasdsd").is_valid());
     }
 
     #[cfg(feature = "serde")]
     #[test]
     fn serialize_mxc_uri() {
         assert_eq!(
-            serde_json::to_string(&MxcUri::from("mxc://server/1234id"))
+            serde_json::to_string(&Box::<MxcUri>::from("mxc://server/1234id"))
                 .expect("Failed to convert MxcUri to JSON."),
             r#""mxc://server/1234id""#
         );
@@ -160,7 +104,7 @@ mod tests {
     #[cfg(feature = "serde")]
     #[test]
     fn deserialize_mxc_uri() {
-        let mxc = serde_json::from_str::<MxcUri>(r#""mxc://server/1234id""#)
+        let mxc = serde_json::from_str::<Box<MxcUri>>(r#""mxc://server/1234id""#)
             .expect("Failed to convert JSON to MxcUri");
 
         assert_eq!(mxc.as_str(), "mxc://server/1234id");
diff --git a/crates/ruma-serde-macros/src/outgoing.rs b/crates/ruma-serde-macros/src/outgoing.rs
index ebef8aaf..9ba1117f 100644
--- a/crates/ruma-serde-macros/src/outgoing.rs
+++ b/crates/ruma-serde-macros/src/outgoing.rs
@@ -263,6 +263,7 @@ fn strip_lifetimes(field_type: &mut Type) -> bool {
                         || last_seg.ident == "DeviceId"
                         || last_seg.ident == "DeviceKeyId"
                         || last_seg.ident == "EventId"
+                        || last_seg.ident == "MxcUri"
                         || last_seg.ident == "ServerName"
                         || last_seg.ident == "SessionId"
                         || last_seg.ident == "RawJsonValue"