diff --git a/.github/workflows/lint.yml b/.github/workflows/lint.yml
index f7d4f6a85..e9900d14f 100644
--- a/.github/workflows/lint.yml
+++ b/.github/workflows/lint.yml
@@ -16,8 +16,8 @@ jobs:
       - name: Set up JDK
         uses: actions/setup-java@v3
         with:
-          distribution: 'adopt'
-          java-version: '11'
+          distribution: 'temurin'
+          java-version: '17'
       - name: Formatting
         run: sbt scalafmtSbtCheck scalafmtCheck test:scalafmtCheck
       - name: Scalafix
diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index 4ec73746a..fa5ace919 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -11,8 +11,8 @@ jobs:
     - name: Set up JDK
       uses: actions/setup-java@v3
       with:
-        distribution: 'adopt'
-        java-version: '11'
+        distribution: 'temurin'
+        java-version: '17'
     - uses: harmon758/postgresql-action@v1
       with:
          postgresql version: '10'
diff --git a/Dockerfile b/Dockerfile
index 2d54738d0..ab5154525 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -13,7 +13,7 @@ RUN npm run build
 # Builder image for the Scala app
 # based on https://github.com/hseeberger/scala-sbt
 #
-FROM eclipse-temurin:11-jdk AS scalabuilder
+FROM eclipse-temurin:17-jdk AS scalabuilder
 
 # We need nodejs to run in a reasonable amount of time sbt-web
 # see step `Optimizing JavaScript with RequireJS`
@@ -53,7 +53,7 @@ RUN sbt clean stage
 # Final Image
 #
 #
-FROM eclipse-temurin:11-jre
+FROM eclipse-temurin:17-jre
 
 ENV PLAY_APP_NAME aplus
 ENV PLAY_APP_DIR /var/www/$PLAY_APP_NAME
diff --git a/app.json b/app.json
index a8bc4d4e3..ff78dfb94 100644
--- a/app.json
+++ b/app.json
@@ -46,7 +46,6 @@
       "quantity": 1
     }
   },
-  "stack": "heroku-18",
   "addons": [
     "heroku-postgresql"
   ],
diff --git a/system.properties b/system.properties
index 180a27348..0dc726cec 100644
--- a/system.properties
+++ b/system.properties
@@ -1 +1 @@
-java.runtime.version=11
\ No newline at end of file
+java.runtime.version=17
\ No newline at end of file