diff --git a/.github/workflows/main.yml b/.github/workflows/main.yml
index 38771df..2e897bc 100644
--- a/.github/workflows/main.yml
+++ b/.github/workflows/main.yml
@@ -16,7 +16,7 @@ jobs:
     strategy:
       matrix:
         otp_version: [19.3.6, 20.3.8.26, 21.3.8.16, 22.3.4.2, 23.0.2]
-        os: [ubuntu-latest]
+        os: [ubuntu-18.04]
 
     steps:
     - uses: actions/checkout@v2