diff --git a/.github/workflows/CI.yml b/.github/workflows/CI.yml
index 8b4c4d7..d7f439e 100644
--- a/.github/workflows/CI.yml
+++ b/.github/workflows/CI.yml
@@ -10,6 +10,7 @@ jobs:
       fail-fast: false
       matrix:
         version:
+          - '1'
           - 'nightly'
         os:
           - ubuntu-latest