diff --git a/backend/tests/wm_token_superadmin_guard.rs b/backend/tests/wm_token_superadmin_guard.rs
index 2ebddf90a4..8823cb8707 100644
--- a/backend/tests/wm_token_superadmin_guard.rs
+++ b/backend/tests/wm_token_superadmin_guard.rs
@@ -467,7 +467,22 @@ async fn test_wm_token_rejected_by_instance_admin_gates(db: Pool<Postgres>) -> a
         resp.text().await?
     );
 
-    // 3. Worker-group config: the static env value must be masked for a job token.
+    // 3. The sibling listing spans every workspace's concurrency keys, so it is
+    //    gated the same way as the prune above.
+    let resp = authed(
+        client().get(format!("{base}/concurrency_groups/list")),
+        &sa_wm,
+    )
+    .send()
+    .await?;
+    assert_eq!(
+        resp.status(),
+        401,
+        "superadmin WM_TOKEN must not list global concurrency groups: {}",
+        resp.text().await?
+    );
+
+    // 4. Worker-group config: the static env value must be masked for a job token.
     let body = authed(
         client().get(format!("{base}/configs/list_worker_groups")),
         &sa_wm,
diff --git a/backend/windmill-api-jobs/src/concurrency_groups.rs b/backend/windmill-api-jobs/src/concurrency_groups.rs
index 6d104a5716..2c8f900d2b 100644
--- a/backend/windmill-api-jobs/src/concurrency_groups.rs
+++ b/backend/windmill-api-jobs/src/concurrency_groups.rs
@@ -1,9 +1,8 @@
-use windmill_api_auth::{check_scopes, is_instance_admin, ApiAuthed};
+use windmill_api_auth::{check_scopes, is_instance_admin, require_instance_admin, ApiAuthed};
 use windmill_common::{
     db::{UserDB, DB},
     error::Error::PermissionDenied,
     error::{self, JsonResult},
-    utils::require_admin,
 };
 
 use crate::query::{filter_list_completed_query, filter_list_queue_query};
@@ -43,7 +42,9 @@ async fn list_concurrency_groups(
     authed: ApiAuthed,
     Extension(db): Extension<DB>,
 ) -> JsonResult<Vec<ConcurrencyGroups>> {
-    require_admin(authed.is_admin, &authed.username)?;
+    // Instance-global: the listing spans every workspace's concurrency keys, so a job
+    // token's workspace-admin claim must not reach it (mirrors the prune route below).
+    require_instance_admin(&authed)?;
 
     let concurrency_counts = sqlx::query_as::<_, (String, i64)>(
         "SELECT concurrency_id, (select COUNT(*) from jsonb_object_keys(job_uuids)) as n_job_uuids FROM concurrency_counter",