diff --git a/.github/workflows/ruby_versions.json b/.github/workflows/ruby_versions.json
index 614a449..fecc629 100644
--- a/.github/workflows/ruby_versions.json
+++ b/.github/workflows/ruby_versions.json
@@ -1,4 +1,5 @@
 [
+  "4.0.4",
   "4.0.3",
   "4.0.2",
   "4.0.1",