diff --git a/.github/workflows/build_firefox.yml b/.github/workflows/build_firefox.yml
index b74c648b34..16d905a98f 100644
--- a/.github/workflows/build_firefox.yml
+++ b/.github/workflows/build_firefox.yml
@@ -16,7 +16,7 @@ env:
 jobs:
   ubuntu_18_04:
     name: Ubuntu 18.04
-    runs-on: [self-hosted, ubuntu-18.04]
+    runs-on: [self-hosted, fast-ubuntu-18.04]
     steps:
     - uses: actions/checkout@v2
     - uses: actions/setup-node@v1
diff --git a/.github/workflows/build_webkit.yml b/.github/workflows/build_webkit.yml
index cb9eb0dc2a..e3b20e497f 100644
--- a/.github/workflows/build_webkit.yml
+++ b/.github/workflows/build_webkit.yml
@@ -17,7 +17,7 @@ env:
 jobs:
   ubuntu_18_04:
     name: Ubuntu 18.04
-    runs-on: [self-hosted, ubuntu-18.04]
+    runs-on: [self-hosted, fast-ubuntu-18.04]
     steps:
     - uses: actions/checkout@v2
     - uses: actions/setup-node@v1