diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index 1a361d7..86c2582 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -21,7 +21,7 @@ jobs:
 
     strategy:
       matrix:
-        os: ['ubuntu-18.04', 'ubuntu-20.04', 'macos-latest']
+        os: ['ubuntu-20.04', 'macos-latest']
         cc: ['gcc', 'clang']
 
     steps: