diff --git a/backend/api.js b/backend/api.js
index 3ccd4cc..0eb1834 100644
--- a/backend/api.js
+++ b/backend/api.js
@@ -164,6 +164,10 @@ export class Session {
       }
       this.ws.send(JSON.stringify(msg));
     } catch (err) {
+      if (this.ws.readyState === WebSocket.CLOSED) {
+        // User closed their end, no big deal.
+        return;
+      }
       logError(err);
       await this.teardown();
     }