diff --git a/crates/hir_ty/src/diagnostics/decl_check.rs b/crates/hir_ty/src/diagnostics/decl_check.rs
index 724bad867dd..25587e11686 100644
--- a/crates/hir_ty/src/diagnostics/decl_check.rs
+++ b/crates/hir_ty/src/diagnostics/decl_check.rs
@@ -26,6 +26,7 @@
     ast::{self, NameOwner},
     AstNode, AstPtr,
 };
+use test_utils::mark;
 
 use crate::{
     db::HirDatabase,
@@ -88,6 +89,7 @@ fn allowed(&self, db: &dyn HirDatabase, id: AttrDefId, allow_name: &str) -> bool
     fn validate_func(&mut self, db: &dyn HirDatabase, func: FunctionId) {
         let data = db.function_data(func);
         if data.is_extern {
+            mark::hit!(extern_func_incorrect_case_ignored);
             return;
         }
 
@@ -653,6 +655,7 @@ fn validate_const(&mut self, db: &dyn HirDatabase, const_id: ConstId) {
     fn validate_static(&mut self, db: &dyn HirDatabase, static_id: StaticId) {
         let data = db.static_data(static_id);
         if data.is_extern {
+            mark::hit!(extern_static_incorrect_case_ignored);
             return;
         }
 
@@ -716,6 +719,8 @@ fn pat_equals_to_name(pat: Option<ast::Pat>, name: &Name) -> bool {
 
 #[cfg(test)]
 mod tests {
+    use test_utils::mark;
+
     use crate::diagnostics::tests::check_diagnostics;
 
     #[test]
@@ -930,6 +935,8 @@ pub struct some_type {
 
     #[test]
     fn ignores_extern_items() {
+        mark::check!(extern_func_incorrect_case_ignored);
+        mark::check!(extern_static_incorrect_case_ignored);
         check_diagnostics(
             r#"
 extern {