diff --git a/.circleci/config.yml b/.circleci/config.yml
index 22458d7..e334cc8 100644
--- a/.circleci/config.yml
+++ b/.circleci/config.yml
@@ -39,13 +39,7 @@ workflows:
           ruby_version: "3.0.3"
       - test:
           name: "ruby2-7"
-          ruby_version: "2.7.5"
-      - test:
-          name: "ruby2-6"
-          ruby_version: "2.6.9"
-      - test:
-          name: "ruby2-5"
-          ruby_version: "2.5.9"
+          ruby_version: "2.7.7"
 
   nightly:
     triggers:
@@ -61,10 +55,4 @@ workflows:
           ruby_version: "3.0.3"
       - test:
           name: "ruby2-7"
-          ruby_version: "2.7.5"
-      - test:
-          name: "ruby2-6"
-          ruby_version: "2.6.9"
-      - test:
-          name: "ruby2-5"
-          ruby_version: "2.5.9"
+          ruby_version: "2.7.7"