diff --git a/.github/workflows/publish.yml b/.github/workflows/publish.yml
index 225cb0d..f499530 100644
--- a/.github/workflows/publish.yml
+++ b/.github/workflows/publish.yml
@@ -16,7 +16,7 @@ jobs:
       - name: Setup Java
         uses: actions/setup-java@v4
         with:
-          java-version: 20
+          java-version: 21
           distribution: temurin
 
       - name: Setup Node.js
diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
new file mode 100644
index 0000000..c63c6f7
--- /dev/null
+++ b/.github/workflows/test.yml
@@ -0,0 +1,65 @@
+name: Test
+
+on:
+  push:
+    branches: ['**']
+  pull_request:
+  workflow_call:
+
+concurrency:
+  group: test-${{ github.ref }}
+  cancel-in-progress: true
+
+permissions:
+  contents: read
+
+jobs:
+  checks:
+    name: Checks
+    runs-on: ubuntu-latest
+
+    defaults:
+      run:
+        working-directory: client
+
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+
+      - name: Setup Java
+        uses: actions/setup-java@v4
+        with:
+          java-version: 21
+          distribution: temurin
+
+      - name: Setup Node.js
+        uses: actions/setup-node@v4
+        with:
+          node-version: 22
+          cache: npm
+          cache-dependency-path: client/package-lock.json
+
+      - name: Install dependencies
+        run: npm ci
+
+      - name: Lint
+        run: npm run lint
+
+      - name: Type-check
+        run: npx tsc --noEmit
+
+      - name: Build server
+        working-directory: server
+        run: |
+          mvn -B package
+          mkdir -p ../client/server
+          cp target/language-server-liquidjava.jar ../client/server/
+
+      - name: Package extension
+        run: npx vsce package --out liquid-java.vsix
+
+      - name: Check packaged runtime files
+        run: |
+          unzip -Z1 liquid-java.vsix > /tmp/liquid-java-vsix-files.txt
+          grep -Fx 'extension/dist/server/language-server-liquidjava.jar' /tmp/liquid-java-vsix-files.txt
+          grep -Fx 'extension/media/webview.js' /tmp/liquid-java-vsix-files.txt
diff --git a/server/pom.xml b/server/pom.xml
index 71d1296..31b050c 100644
--- a/server/pom.xml
+++ b/server/pom.xml
@@ -36,10 +36,6 @@
                 <groupId>org.apache.maven.plugins</groupId>
                 <artifactId>maven-compiler-plugin</artifactId>
                 <version>${pVersion.compiler}</version>
-                <configuration>
-					<source>20</source>
-					<target>20</target>
-				</configuration>
             </plugin>
 			<plugin>
 				<groupId>org.apache.maven.plugins</groupId>
@@ -102,8 +98,7 @@
     <properties>
         <lsp4j.version>0.24.0</lsp4j.version>
         <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
-		<maven.compiler.source>20</maven.compiler.source>
-		<maven.compiler.target>20</maven.compiler.target>
+		<maven.compiler.release>20</maven.compiler.release>
 		<!-- versions -->
 		<version.memcompiler>1.3.0</version.memcompiler>
 		<version.spoon>10.4.2</version.spoon>