diff --git a/.github/workflows/test-backend.yml b/.github/workflows/test-backend.yml
index 3a3e27863..19496c895 100644
--- a/.github/workflows/test-backend.yml
+++ b/.github/workflows/test-backend.yml
@@ -13,7 +13,7 @@ jobs:
 
     strategy:
       matrix:
-        node-version: [20.x]
+        node-version: [20.5.1]
 
     services:
       postgres:
diff --git a/.github/workflows/test-frontend.yml b/.github/workflows/test-frontend.yml
index 998a19161..0618a0ef0 100644
--- a/.github/workflows/test-frontend.yml
+++ b/.github/workflows/test-frontend.yml
@@ -13,7 +13,7 @@ jobs:
 
     strategy:
       matrix:
-        node-version: [20.x]
+        node-version: [20.5.1]
 
     steps:
     - uses: actions/checkout@v4.0.0
@@ -51,7 +51,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        node-version: [20.x]
+        node-version: [20.5.1]
         browser: [chrome]
 
     services:
diff --git a/.github/workflows/test-misskey-js.yml b/.github/workflows/test-misskey-js.yml
index d1d3013a2..7999c183b 100644
--- a/.github/workflows/test-misskey-js.yml
+++ b/.github/workflows/test-misskey-js.yml
@@ -16,7 +16,7 @@ jobs:
 
     strategy:
       matrix:
-        node-version: [20.x]
+        node-version: [20.5.1]
         # See supported Node.js release schedule at https://nodejs.org/en/about/releases/
 
     steps:
diff --git a/.github/workflows/test-production.yml b/.github/workflows/test-production.yml
index 16517d137..0504f42d1 100644
--- a/.github/workflows/test-production.yml
+++ b/.github/workflows/test-production.yml
@@ -16,7 +16,7 @@ jobs:
 
     strategy:
       matrix:
-        node-version: [20.x]
+        node-version: [20.5.1]
 
     steps:
     - uses: actions/checkout@v4.0.0