diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index a7f86f42..a1fee1f5 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -24,7 +24,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        ruby: [ 2.1, 2.2, 2.3, 2.4, 2.5, 2.6, 2.7, "3.0", jruby-9.1.17.0, jruby-9.2.17.0 ]
+        ruby: [ "1.9.3", "2.0.0", 2.1, 2.2, 2.3, 2.4, 2.5, 2.6, 2.7, "3.0", jruby-9.1, jruby-9.2, jruby-9.3 ]
     name: ${{ matrix.ruby }}
     env:
       BUNDLE_GEMFILE: .ci.gemfile