diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 51ed9619..e1e263c4 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -27,7 +27,7 @@ jobs:
     strategy:
       matrix:
         os: [ubuntu-latest]
-        scala: [2.12.20, 2.13.18, 3.3.7]
+        scala: [2.12.21, 2.13.18, 3.3.7]
         java: [zulu@11]
     runs-on: ${{ matrix.os }}
     steps:
@@ -88,12 +88,12 @@ jobs:
       - name: Setup sbt
         uses: sbt/setup-sbt@v1
 
-      - name: Download target directories (2.12.20)
+      - name: Download target directories (2.12.21)
         uses: actions/download-artifact@v6
         with:
-          name: target-${{ matrix.os }}-2.12.20-${{ matrix.java }}
+          name: target-${{ matrix.os }}-2.12.21-${{ matrix.java }}
 
-      - name: Inflate target directories (2.12.20)
+      - name: Inflate target directories (2.12.21)
         run: |
           tar xf targets.tar
           rm targets.tar
diff --git a/build.sbt b/build.sbt
index 111b1dd0..5eb6befb 100644
--- a/build.sbt
+++ b/build.sbt
@@ -21,7 +21,7 @@ inThisBuild(
 
 def crossPlugin(x: sbt.librarymanagement.ModuleID) = compilerPlugin(x.cross(CrossVersion.full))
 
-val Scala212 = "2.12.20"
+val Scala212 = "2.12.21"
 val Scala213 = "2.13.18"
 val Scala3 = "3.3.7"