diff --git a/.changeset/upgrade-tajriba.md b/.changeset/upgrade-tajriba.md
new file mode 100644
index 00000000..b4b5109d
--- /dev/null
+++ b/.changeset/upgrade-tajriba.md
@@ -0,0 +1,5 @@
+---
+"@empirica/core": patch
+---
+
+Upgrade Tajriba to v1.7.1 (concurrency fixes).
diff --git a/go.mod b/go.mod
index 7e4964b4..d4785007 100644
--- a/go.mod
+++ b/go.mod
@@ -12,7 +12,8 @@ require (
 	github.com/charmbracelet/lipgloss v0.5.0
 	github.com/cortesi/moddwatch v0.0.0-20210323234936-df014e95c743
 	github.com/davecgh/go-spew v1.1.1
-	github.com/empiricaly/tajriba v1.7.0
+	github.com/empiricaly/tajriba v1.7.1
+	github.com/go-bindata/go-bindata v3.1.2+incompatible
 	github.com/go-playground/validator/v10 v10.11.0
 	github.com/jpillora/backoff v1.0.0
 	github.com/json-iterator/go v1.1.12
@@ -47,7 +48,6 @@ require (
 	github.com/cpuguy83/go-md2man/v2 v2.0.2 // indirect
 	github.com/fatih/color v1.13.0 // indirect
 	github.com/fsnotify/fsnotify v1.5.4 // indirect
-	github.com/go-bindata/go-bindata v3.1.2+incompatible // indirect
 	github.com/go-logr/logr v1.2.4 // indirect
 	github.com/go-playground/locales v0.14.0 // indirect
 	github.com/go-playground/universal-translator v0.18.0 // indirect
diff --git a/go.sum b/go.sum
index 9035e3f0..11471e5f 100644
--- a/go.sum
+++ b/go.sum
@@ -91,8 +91,8 @@ github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c
 github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/dgryski/trifles v0.0.0-20200323201526-dd97f9abfb48 h1:fRzb/w+pyskVMQ+UbP35JkH8yB7MYb4q/qhBarqZE6g=
 github.com/dgryski/trifles v0.0.0-20200323201526-dd97f9abfb48/go.mod h1:if7Fbed8SFyPtHLHbg49SI7NAdJiC5WIA09pe59rfAA=
-github.com/empiricaly/tajriba v1.7.0 h1:3WdJqOIPrdJmdWZEs7ngH20ghu27sJjqK+KKy54iY4U=
-github.com/empiricaly/tajriba v1.7.0/go.mod h1:SvDTEUhhlQTQI1uBB8AWWR1cKzbE+zOfpJCm0Adkdyw=
+github.com/empiricaly/tajriba v1.7.1 h1:J+69HkzwqzEvWpdahuFQyp1iL6b31Fe/WEQRKzTI/R8=
+github.com/empiricaly/tajriba v1.7.1/go.mod h1:SvDTEUhhlQTQI1uBB8AWWR1cKzbE+zOfpJCm0Adkdyw=
 github.com/envoyproxy/go-control-plane v0.9.0/go.mod h1:YTl/9mNaCwkRvm6d1a2C3ymFceY/DCBVvsKhRF0iEA4=
 github.com/envoyproxy/go-control-plane v0.9.1-0.20191026205805-5f8ba28d4473/go.mod h1:YTl/9mNaCwkRvm6d1a2C3ymFceY/DCBVvsKhRF0iEA4=
 github.com/envoyproxy/go-control-plane v0.9.4/go.mod h1:6rpuAdCZL397s3pYoYcLgu1mIlRU8Am5FuJP05cCM98=
diff --git a/tests/stress/experiment/client/package-lock.json b/tests/stress/experiment/client/package-lock.json
index 467a72b7..f6bfec77 100644
--- a/tests/stress/experiment/client/package-lock.json
+++ b/tests/stress/experiment/client/package-lock.json
@@ -23,6 +23,9 @@
         "unocss": "^0.51.4",
         "vite": "2.9.15",
         "vite-plugin-restart": "0.1.1"
+      },
+      "engines": {
+        "node": ">= 20.12.0"
       }
     },
     "node_modules/@ampproject/remapping": {
diff --git a/tests/stress/experiment/server/package-lock.json b/tests/stress/experiment/server/package-lock.json
index e374f492..234a2b6e 100644
--- a/tests/stress/experiment/server/package-lock.json
+++ b/tests/stress/experiment/server/package-lock.json
@@ -11,6 +11,9 @@
       },
       "devDependencies": {
         "esbuild": "0.14.47"
+      },
+      "engines": {
+        "node": ">= 20.12.0"
       }
     },
     "node_modules/@empirica/core": {
diff --git a/tests/stress/tests/assignment.spec.js b/tests/stress/tests/assignment.spec.js
index 8bc3bd91..afdf639f 100644
--- a/tests/stress/tests/assignment.spec.js
+++ b/tests/stress/tests/assignment.spec.js
@@ -67,7 +67,7 @@ test("reassignment after game end", async ({ browser }) => {
 
 // This tests whether the player can be reassigned after the first game of the
 // player ends, into a game with different players.
-test.only("reassignment after game end with different players", async ({
+test("reassignment after game end with different players", async ({
   browser,
 }) => {
   const ctx = new Context(browser);
diff --git a/tests/stress/tests/main.spec.js b/tests/stress/tests/main.spec.js
index 234c807a..930713bf 100644
--- a/tests/stress/tests/main.spec.js
+++ b/tests/stress/tests/main.spec.js
@@ -119,7 +119,7 @@ test.skip("4 x 10 player - staggered arrival", async ({ browser }) => {
 // (there's a race condition between the time of assignment and fetching the
 // number of players in the game). AND why overflow is not working as expected.
 // First need to debug overflow.
-test.skip("4 x 10 player - concurrent arrival", async ({ browser }) => {
+test("4 x 10 player - concurrent arrival", async ({ browser }) => {
   const ctx = new Context(browser);
 
   ctx.logMatching(/stage started/);
diff --git a/tools.go b/tools.go
new file mode 100644
index 00000000..dd6eaed1
--- /dev/null
+++ b/tools.go
@@ -0,0 +1,10 @@
+//go:build tools
+// +build tools
+
+// package tools is a place to list all tools used in go generate and tests, so
+// that `go mod tidy` will not shoot down all those deps.
+package tools
+
+import (
+	_ "github.com/go-bindata/go-bindata"
+)