diff --git a/app/routers/admin.py b/app/routers/admin.py
index c29767b..0b57f7e 100644
--- a/app/routers/admin.py
+++ b/app/routers/admin.py
@@ -116,10 +116,16 @@ async def delete_user(user_id: int, _admin=Depends(admin_required)):
         user = conn.execute("SELECT id FROM users WHERE id=?", (user_id,)).fetchone()
         if not user:
             return JSONResponse({"error": "User not found"}, status_code=404)
+        # Cascade delete: first delete child records
         conn.execute("DELETE FROM login_history WHERE user_id=?", (user_id,))
         conn.execute("DELETE FROM user_oauth_tokens WHERE user_id=?", (user_id,))
         conn.execute("DELETE FROM user_tokens WHERE gitea_user_id=?", (user_id,))
-        conn.execute("DELETE FROM pages WHERE owner_id=?", (user_id,))
+        conn.execute("DELETE FROM workspace_members WHERE user_id=?", (user_id,))
+        # Delete workspaces owned by this user
+        ws_rows = conn.execute("SELECT id FROM workspaces WHERE owner_id=?", (user_id,)).fetchall()
+        for ws in ws_rows:
+            conn.execute("DELETE FROM pages WHERE workspace_id=?", (ws["id"],))
+            conn.execute("DELETE FROM workspace_members WHERE workspace_id=?", (ws["id"],))
         conn.execute("DELETE FROM workspaces WHERE owner_id=?", (user_id,))
         conn.execute("DELETE FROM users WHERE id=?", (user_id,))
         conn.commit()