diff --git a/crates/ruff/src/rules/flake8_no_pep420/rules.rs b/crates/ruff/src/rules/flake8_no_pep420/rules.rs
index 879a431f6d..eba6c4c545 100644
--- a/crates/ruff/src/rules/flake8_no_pep420/rules.rs
+++ b/crates/ruff/src/rules/flake8_no_pep420/rules.rs
@@ -28,12 +28,14 @@ define_violation!(
     /// [`namespace-packages`](https://github.com/charliermarsh/ruff#namespace-packages)
     /// configuration option. Adding a namespace package to the configuration
     /// will suppress this violation for a given package.
-    pub struct ImplicitNamespacePackage(pub String);
+    pub struct ImplicitNamespacePackage {
+        pub filename: String,
+    }
 );
 impl Violation for ImplicitNamespacePackage {
     #[derive_message_formats]
     fn message(&self) -> String {
-        let ImplicitNamespacePackage(filename) = self;
+        let ImplicitNamespacePackage { filename } = self;
         format!("File `{filename}` is part of an implicit namespace package. Add an `__init__.py`.")
     }
 }
@@ -62,7 +64,9 @@ pub fn implicit_namespace_package(
             .to_string_lossy()
             .replace(std::path::MAIN_SEPARATOR, "/"); // The snapshot test expects / as the path separator.
         Some(Diagnostic::new(
-            ImplicitNamespacePackage(fs::relativize_path(path)),
+            ImplicitNamespacePackage {
+                filename: fs::relativize_path(path),
+            },
             Range::default(),
         ))
     } else {
diff --git a/crates/ruff/src/rules/flake8_no_pep420/snapshots/ruff__rules__flake8_no_pep420__tests__test_fail_empty.snap b/crates/ruff/src/rules/flake8_no_pep420/snapshots/ruff__rules__flake8_no_pep420__tests__test_fail_empty.snap
index 3014b3b07d..9d70d2f5eb 100644
--- a/crates/ruff/src/rules/flake8_no_pep420/snapshots/ruff__rules__flake8_no_pep420__tests__test_fail_empty.snap
+++ b/crates/ruff/src/rules/flake8_no_pep420/snapshots/ruff__rules__flake8_no_pep420__tests__test_fail_empty.snap
@@ -3,7 +3,8 @@ source: crates/ruff/src/rules/flake8_no_pep420/mod.rs
 expression: diagnostics
 ---
 - kind:
-    ImplicitNamespacePackage: "./resources/test/fixtures/flake8_no_pep420/test_fail_empty/example.py"
+    ImplicitNamespacePackage:
+      filename: "./resources/test/fixtures/flake8_no_pep420/test_fail_empty/example.py"
   location:
     row: 1
     column: 0
diff --git a/crates/ruff/src/rules/flake8_no_pep420/snapshots/ruff__rules__flake8_no_pep420__tests__test_fail_nonempty.snap b/crates/ruff/src/rules/flake8_no_pep420/snapshots/ruff__rules__flake8_no_pep420__tests__test_fail_nonempty.snap
index 2a18c0978c..5283b87f2d 100644
--- a/crates/ruff/src/rules/flake8_no_pep420/snapshots/ruff__rules__flake8_no_pep420__tests__test_fail_nonempty.snap
+++ b/crates/ruff/src/rules/flake8_no_pep420/snapshots/ruff__rules__flake8_no_pep420__tests__test_fail_nonempty.snap
@@ -3,7 +3,8 @@ source: crates/ruff/src/rules/flake8_no_pep420/mod.rs
 expression: diagnostics
 ---
 - kind:
-    ImplicitNamespacePackage: "./resources/test/fixtures/flake8_no_pep420/test_fail_nonempty/example.py"
+    ImplicitNamespacePackage:
+      filename: "./resources/test/fixtures/flake8_no_pep420/test_fail_nonempty/example.py"
   location:
     row: 1
     column: 0
diff --git a/crates/ruff/src/rules/flake8_no_pep420/snapshots/ruff__rules__flake8_no_pep420__tests__test_fail_shebang.snap b/crates/ruff/src/rules/flake8_no_pep420/snapshots/ruff__rules__flake8_no_pep420__tests__test_fail_shebang.snap
index 3f911eac83..045403c811 100644
--- a/crates/ruff/src/rules/flake8_no_pep420/snapshots/ruff__rules__flake8_no_pep420__tests__test_fail_shebang.snap
+++ b/crates/ruff/src/rules/flake8_no_pep420/snapshots/ruff__rules__flake8_no_pep420__tests__test_fail_shebang.snap
@@ -3,7 +3,8 @@ source: crates/ruff/src/rules/flake8_no_pep420/mod.rs
 expression: diagnostics
 ---
 - kind:
-    ImplicitNamespacePackage: "./resources/test/fixtures/flake8_no_pep420/test_fail_shebang/example.py"
+    ImplicitNamespacePackage:
+      filename: "./resources/test/fixtures/flake8_no_pep420/test_fail_shebang/example.py"
   location:
     row: 1
     column: 0