diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index a4595fc..642222f 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -8,7 +8,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        ruby: [ '2.5', '2.6', '2.7', '3.0' ]
+        ruby: [ '2.6', '2.7', '3.0' ]
     steps:
       - uses: actions/checkout@v2
       - name: Install BLAS and LAPACK