diff --git a/CHANGELOG.md b/CHANGELOG.md
index 6fa8c2d65b..3ede9c1fda 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -9,6 +9,7 @@
 - Extract op and description while converting opentelemetry spans to sentry spans. ([#3287](https://github.com/getsentry/relay/pull/3287))
 - Drop `event_id` and `remote_addr` from all outcomes. ([#3319](https://github.com/getsentry/relay/pull/3319))
 - Support for AI token metrics ([#3250](https://github.com/getsentry/relay/pull/3250))
+- Accept integers in `event.user.username`. ([#3328](https://github.com/getsentry/relay/pull/3328))
 
 **Internal**:
 
diff --git a/relay-event-normalization/src/event.rs b/relay-event-normalization/src/event.rs
index d292503723..0d2c9bcaab 100644
--- a/relay-event-normalization/src/event.rs
+++ b/relay-event-normalization/src/event.rs
@@ -2973,7 +2973,7 @@ mod tests {
             Annotated::new(map)
         });
         assert_eq!(user.other, Object::new());
-        assert_eq!(user.username, Annotated::new("john".to_string()));
+        assert_eq!(user.username, Annotated::new("john".to_string().into()));
         assert_eq!(user.sentry_user, Annotated::new("id:123456".to_string()));
     }
 
diff --git a/relay-event-normalization/src/normalize/utils.rs b/relay-event-normalization/src/normalize/utils.rs
index cc7a86c772..aabc4bb9b5 100644
--- a/relay-event-normalization/src/normalize/utils.rs
+++ b/relay-event-normalization/src/normalize/utils.rs
@@ -205,7 +205,7 @@ mod tests {
         // has to be changed. Though it is probably not a good idea!
         let user = User {
             id: Annotated::new("ident".to_owned().into()),
-            username: Annotated::new("username".to_owned()),
+            username: Annotated::new("username".to_owned().into()),
             email: Annotated::new("email".to_owned()),
             ip_address: Annotated::new("127.0.0.1".parse().unwrap()),
             ..User::default()
@@ -214,7 +214,7 @@ mod tests {
         assert_eq!(get_event_user_tag(&user).unwrap(), "id:ident");
 
         let user = User {
-            username: Annotated::new("username".to_owned()),
+            username: Annotated::new("username".to_owned().into()),
             email: Annotated::new("email".to_owned()),
             ip_address: Annotated::new("127.0.0.1".parse().unwrap()),
             ..User::default()
diff --git a/relay-event-schema/src/protocol/user.rs b/relay-event-schema/src/protocol/user.rs
index 6738f827ba..88263fa9c0 100644
--- a/relay-event-schema/src/protocol/user.rs
+++ b/relay-event-schema/src/protocol/user.rs
@@ -62,7 +62,7 @@ pub struct User {
 
     /// Username of the user.
     #[metastructure(pii = "true", max_chars = 128, skip_serialization = "empty")]
-    pub username: Annotated<String>,
+    pub username: Annotated<LenientString>,
 
     /// Human readable name of the user.
     #[metastructure(pii = "true", max_chars = 128, skip_serialization = "empty")]
@@ -163,7 +163,7 @@ mod tests {
             email: Annotated::new("mail@example.org".to_string()),
             ip_address: Annotated::new(IpAddr::auto()),
             name: Annotated::new("John Doe".to_string()),
-            username: Annotated::new("john_doe".to_string()),
+            username: Annotated::new(LenientString("john_doe".to_owned())),
             geo: Annotated::empty(),
             segment: Annotated::new("vip".to_string()),
             data: {
@@ -202,6 +202,19 @@ mod tests {
         assert_eq!(output, user.to_json().unwrap());
     }
 
+    #[test]
+    fn test_user_lenient_username() {
+        let input = r#"{"username":42}"#;
+        let output = r#"{"username":"42"}"#;
+        let user = Annotated::new(User {
+            username: Annotated::new("42".to_string().into()),
+            ..User::default()
+        });
+
+        assert_eq!(user, Annotated::from_json(input).unwrap());
+        assert_eq!(output, user.to_json().unwrap());
+    }
+
     #[test]
     fn test_user_invalid_id() {
         let json = r#"{"id":[]}"#;
diff --git a/relay-pii/src/snapshots/relay_pii__processor__tests__scrub_original_value.snap b/relay-pii/src/snapshots/relay_pii__processor__tests__scrub_original_value.snap
index 8a4421213b..9fad3a9cb8 100644
--- a/relay-pii/src/snapshots/relay_pii__processor__tests__scrub_original_value.snap
+++ b/relay-pii/src/snapshots/relay_pii__processor__tests__scrub_original_value.snap
@@ -47,7 +47,9 @@ Event {
             ),
         },
         username: Annotated(
-            "hey  man [ip]",
+            LenientString(
+                "hey  man [ip]",
+            ),
             Meta {
                 remarks: [
                     Remark {
diff --git a/relay-server/src/utils/unreal.rs b/relay-server/src/utils/unreal.rs
index ac6e62283c..03990a62dc 100644
--- a/relay-server/src/utils/unreal.rs
+++ b/relay-server/src/utils/unreal.rs
@@ -196,7 +196,7 @@ fn merge_unreal_context(event: &mut Event, context: Unreal4Context) {
             .user
             .get_or_insert_with(User::default)
             .username
-            .set_value(Some(username));
+            .set_value(Some(username.into()));
     }
 
     let contexts = event.contexts.get_or_insert_with(Contexts::default);