diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index 3ffeeee..6226037 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -13,9 +13,11 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        os: [ubuntu-latest, windows-latest]
+        os:
+          - ubuntu-18.04
+          - windows-latest
         include:
-          - os: ubuntu-latest
+          - os: ubuntu-18.04
             os_short: linux
           - os: windows-latest
             os_short: windows