diff --git a/.github/workflows/ci.yaml b/.github/workflows/ci.yaml
index f50f278..2ef08ab 100644
--- a/.github/workflows/ci.yaml
+++ b/.github/workflows/ci.yaml
@@ -17,7 +17,7 @@ jobs:
     strategy:
       matrix:
         operating-system: ['ubuntu-latest']
-        php-version: ['5.6', '7.0', '7.1', '7.2', '7.3', '7.4', '8.0']
+        php-version: ['5.6', '7.0', '7.1', '7.2', '7.3', '7.4', '8.0', '8.1']
 
     name: CI on ${{ matrix.operating-system }} with PHP ${{ matrix.php-version }}