diff --git a/workspace-server/internal/handlers/workspace_broadcast.go b/workspace-server/internal/handlers/workspace_broadcast.go
index 27ce7a8ea..d0baa3352 100644
--- a/workspace-server/internal/handlers/workspace_broadcast.go
+++ b/workspace-server/internal/handlers/workspace_broadcast.go
@@ -82,18 +82,21 @@ func (h *BroadcastHandler) Broadcast(c *gin.Context) {
 	// Find the sender's org root by walking the parent_id chain.
 	// Workspaces with parent_id = NULL are org roots; every other workspace
 	// belongs to the org identified by its topmost ancestor.
+	// Uses the same CTE shape as org_scope.go (#1954) — the recursive seed
+	// must NOT carry `id AS root_id` because that resolves non-root senders
+	// to themselves instead of their true org root (availability bug #1959).
 	var orgRootID string
 	err = db.DB.QueryRowContext(ctx, `
 		WITH RECURSIVE org_chain AS (
-			SELECT id, parent_id, id AS root_id
+			SELECT id, parent_id
 			FROM workspaces
 			WHERE id = $1
 			UNION ALL
-			SELECT w.id, w.parent_id, c.root_id
+			SELECT w.id, w.parent_id
 			FROM workspaces w
 			JOIN org_chain c ON w.id = c.parent_id
 		)
-		SELECT root_id FROM org_chain WHERE parent_id IS NULL LIMIT 1
+		SELECT id AS root_id FROM org_chain WHERE parent_id IS NULL LIMIT 1
 	`, senderID).Scan(&orgRootID)
 	if err != nil {
 		log.Printf("Broadcast: org root lookup for %s: %v", senderID, err)