diff --git a/.github/workflows/CI.yml b/.github/workflows/CI.yml
index cd49868..58376f5 100644
--- a/.github/workflows/CI.yml
+++ b/.github/workflows/CI.yml
@@ -19,6 +19,7 @@ jobs:
       fail-fast: false
       matrix:
         version:
+          - '1.5'
           - '1.9'
           - 'nightly'
         os: