diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 53a9d36f..a7eb3c5e 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -29,7 +29,7 @@ jobs:
       matrix:
         os: [ubuntu-22.04]
         scala: [2.11.12, 2.12.14, 2.13.6]
-        java: [temurin@8, temurin@11, temurin@17, temurin@21]
+        java: [temurin@8, temurin@11, temurin@17]
     runs-on: ${{ matrix.os }}
     timeout-minutes: 60
     steps:
@@ -80,19 +80,6 @@ jobs:
         if: matrix.java == 'temurin@17' && steps.setup-java-temurin-17.outputs.cache-hit == 'false'
         run: sbt +update
 
-      - name: Setup Java (temurin@21)
-        id: setup-java-temurin-21
-        if: matrix.java == 'temurin@21'
-        uses: actions/setup-java@v4
-        with:
-          distribution: temurin
-          java-version: 21
-          cache: sbt
-
-      - name: sbt update
-        if: matrix.java == 'temurin@21' && steps.setup-java-temurin-21.outputs.cache-hit == 'false'
-        run: sbt +update
-
       - name: Check that workflows are up to date
         run: sbt githubWorkflowCheck
 
@@ -175,19 +162,6 @@ jobs:
         if: matrix.java == 'temurin@17' && steps.setup-java-temurin-17.outputs.cache-hit == 'false'
         run: sbt +update
 
-      - name: Setup Java (temurin@21)
-        id: setup-java-temurin-21
-        if: matrix.java == 'temurin@21'
-        uses: actions/setup-java@v4
-        with:
-          distribution: temurin
-          java-version: 21
-          cache: sbt
-
-      - name: sbt update
-        if: matrix.java == 'temurin@21' && steps.setup-java-temurin-21.outputs.cache-hit == 'false'
-        run: sbt +update
-
       - name: Download target directories (2.11.12)
         uses: actions/download-artifact@v4
         with:
@@ -298,19 +272,6 @@ jobs:
         if: matrix.java == 'temurin@17' && steps.setup-java-temurin-17.outputs.cache-hit == 'false'
         run: sbt +update
 
-      - name: Setup Java (temurin@21)
-        id: setup-java-temurin-21
-        if: matrix.java == 'temurin@21'
-        uses: actions/setup-java@v4
-        with:
-          distribution: temurin
-          java-version: 21
-          cache: sbt
-
-      - name: sbt update
-        if: matrix.java == 'temurin@21' && steps.setup-java-temurin-21.outputs.cache-hit == 'false'
-        run: sbt +update
-
       - name: Submit Dependencies
         uses: scalacenter/sbt-dependency-submission@v2
         with:
diff --git a/build.sbt b/build.sbt
index a4977e5b..eb6a83e3 100644
--- a/build.sbt
+++ b/build.sbt
@@ -26,7 +26,7 @@ crossScalaVersions := Seq("2.11.12", "2.12.14", "2.13.6")
 ThisBuild / organization := "com.comcast.sirius"
 ThisBuild / organizationName := "Comcast Cable Communications Management, LLC"
 ThisBuild / startYear := Some(2012)
-ThisBuild / githubWorkflowJavaVersions := Seq(JavaSpec.temurin("8"), JavaSpec.temurin("11"), JavaSpec.temurin("17"), JavaSpec.temurin("21"))
+ThisBuild / githubWorkflowJavaVersions := Seq(JavaSpec.temurin("8"), JavaSpec.temurin("11"), JavaSpec.temurin("17"))
 ThisBuild / githubWorkflowScalaVersions := crossScalaVersions.value
 ThisBuild / tlCiMimaBinaryIssueCheck := false