diff --git a/crates/ruma-common/src/events/room/message/image.rs b/crates/ruma-common/src/events/room/message/image.rs
index 19f78f2f..eee0fae6 100644
--- a/crates/ruma-common/src/events/room/message/image.rs
+++ b/crates/ruma-common/src/events/room/message/image.rs
@@ -133,7 +133,7 @@ impl ImageMessageEventContent {
             #[cfg(feature = "unstable-msc3552")]
             file: Some(FileContent::encrypted(file.url.clone(), (&file).into(), None)),
             #[cfg(feature = "unstable-msc3552")]
-            image: Some(Box::new(ImageContent::default())),
+            image: Some(Box::default()),
             #[cfg(feature = "unstable-msc3552")]
             thumbnail: None,
             #[cfg(feature = "unstable-msc3552")]
diff --git a/crates/ruma-common/src/events/room/message/video.rs b/crates/ruma-common/src/events/room/message/video.rs
index 10329d86..3c586718 100644
--- a/crates/ruma-common/src/events/room/message/video.rs
+++ b/crates/ruma-common/src/events/room/message/video.rs
@@ -139,7 +139,7 @@ impl VideoMessageEventContent {
             #[cfg(feature = "unstable-msc3553")]
             file: Some(FileContent::encrypted(file.url.clone(), (&file).into(), None)),
             #[cfg(feature = "unstable-msc3553")]
-            video: Some(Box::new(VideoContent::default())),
+            video: Some(Box::default()),
             #[cfg(feature = "unstable-msc3553")]
             thumbnail: None,
             #[cfg(feature = "unstable-msc3553")]
diff --git a/crates/ruma-common/src/identifiers/user_id.rs b/crates/ruma-common/src/identifiers/user_id.rs
index e68d2bbd..5ea50dc8 100644
--- a/crates/ruma-common/src/identifiers/user_id.rs
+++ b/crates/ruma-common/src/identifiers/user_id.rs
@@ -91,7 +91,7 @@ impl UserId {
 
     /// Returns the user's localpart.
     pub fn localpart(&self) -> &str {
-        &self.as_str()[1..self.colon_idx() as usize]
+        &self.as_str()[1..self.colon_idx()]
     }
 
     /// Returns the server name of the user ID.