diff --git a/src/server/DetoxServer.js b/src/server/DetoxServer.js
index 1ab5f08690bfd3fae42b29ffead720df06a40059..737c4471018c4c75298fc5841ebdf6163dce3d65 100644
--- a/src/server/DetoxServer.js
+++ b/src/server/DetoxServer.js
@@ -107,6 +107,15 @@ class DetoxServer {
     }, timeoutValue);
 
     try {
+      // ws >=8 only invokes the close() callback once every client connection is
+      // closed; a lingering app connection otherwise keeps the server (and the node
+      // process) alive until the test job times out. force-terminate any remaining
+      // clients first so close() resolves immediately.
+      if (this._wss.clients) {
+        for (const client of this._wss.clients) {
+          client.terminate();
+        }
+      }
       this._wss.close(() => {
         clearTimeout(handle);
         this._closing.resolve();