diff --git a/.circleci/config.yml b/.circleci/config.yml
index ec16d9e..147bd62 100644
--- a/.circleci/config.yml
+++ b/.circleci/config.yml
@@ -120,7 +120,7 @@ jobs:
     working_directory: ~/repo
 
     environment:
-      SCALA_VERSION: 2.12.20
+      SCALA_VERSION: 2.12.21
     
     steps:
       - checkout
diff --git a/compiler.sbt b/compiler.sbt
index 5afb8e0..225ef84 100644
--- a/compiler.sbt
+++ b/compiler.sbt
@@ -1,4 +1,4 @@
-ThisBuild / scalaVersion := "2.12.20"
+ThisBuild / scalaVersion := "2.12.21"
 
 val scala3Lts = "3.3.7"