diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 2d01d76a446f420cddd0e3f0858e3a887bf3aa28..0e68a0165b3afa0be1202327d9eaff47f12791ef 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -44,7 +44,7 @@ jobs:
         runs-on: ubuntu-latest
         strategy:
             matrix:
-                python-version: [3.6, 3.7, 3.8]
+                python-version: ["3.6", "3.7", "3.8", "3.9"]
         steps:
         -   uses: actions/checkout@v2
         -