diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index 77b044de..f7d5efdc 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -7,10 +7,10 @@ jobs:
     runs-on: ubuntu-latest
     steps:
     - uses: actions/checkout@v2
-    - name: Set up JDK 1.8
+    - name: Set up JDK 11
       uses: actions/setup-java@v1
       with:
-        java-version: 1.8
+        java-version: 11
     - name: Grant execute permission for gradlew
       run: chmod +x gradlew
     - name: Build with Gradle
diff --git a/.github/workflows/deploy.yml b/.github/workflows/deploy.yml
index d3e5e4df..d177a3f6 100644
--- a/.github/workflows/deploy.yml
+++ b/.github/workflows/deploy.yml
@@ -15,10 +15,10 @@ jobs:
       uses: actions/setup-node@v2
     - name: Set up vsce
       run: npm install -g vsce
-    - name: Set up JDK 1.8
+    - name: Set up JDK 11
       uses: actions/setup-java@v1
       with:
-        java-version: 1.8
+        java-version: 11
     - name: Build with Gradle
       run: |
         chmod +x gradlew
diff --git a/.github/workflows/publish.yml b/.github/workflows/publish.yml
index a94f5ce2..1ebdbaee 100644
--- a/.github/workflows/publish.yml
+++ b/.github/workflows/publish.yml
@@ -10,7 +10,7 @@ jobs:
       - uses: actions/checkout@v2
       - uses: actions/setup-java@v1
         with:
-          java-version: 1.8
+          java-version: 11
       - name: Publish package
         run: ./gradlew publish
         env:
diff --git a/build.gradle b/build.gradle
index 802da0d8..6cc4d2ec 100644
--- a/build.gradle
+++ b/build.gradle
@@ -1,6 +1,6 @@
 plugins {
   id 'org.ec4j.editorconfig' version '0.0.3'
-  id 'org.xtext.builder' version '2.0.8'
+  id 'org.xtext.builder' version '4.0.0'
   id 'io.github.0ffz.github-packages' version '1.2.1'
 }
 
diff --git a/metafix/src/test/java/org/metafacture/metafix/MetafixMethodTest.java b/metafix/src/test/java/org/metafacture/metafix/MetafixMethodTest.java
index 58788e71..c48f8869 100644
--- a/metafix/src/test/java/org/metafacture/metafix/MetafixMethodTest.java
+++ b/metafix/src/test/java/org/metafacture/metafix/MetafixMethodTest.java
@@ -2310,7 +2310,7 @@ public void copyFieldToSubfieldOfArrayOfObjectsWithExplicitAppend() {
 
     @Test
     public void copyFieldToSubfieldOfArrayOfStringsWithIndexImplicitAppend() {
-        MetafixTestHelpers.assertProcessException(IndexOutOfBoundsException.class, "Index: 0, Size: 0", () ->
+        MetafixTestHelpers.assertProcessException(IndexOutOfBoundsException.class, "Index 0 out of bounds for length 0", () ->
             MetafixTestHelpers.assertFix(streamReceiver, Arrays.asList(
                     "set_array('test[]')",
                     "copy_field('key', 'test[].1')"
diff --git a/metafix/src/test/resources/org/metafacture/metafix/integration/record/fromJson/toJson/copy_fieldToArrayOfStringsWithIndex/expected.err b/metafix/src/test/resources/org/metafacture/metafix/integration/record/fromJson/toJson/copy_fieldToArrayOfStringsWithIndex/expected.err
index e9f060a1..215c0f4e 100644
--- a/metafix/src/test/resources/org/metafacture/metafix/integration/record/fromJson/toJson/copy_fieldToArrayOfStringsWithIndex/expected.err
+++ b/metafix/src/test/resources/org/metafacture/metafix/integration/record/fromJson/toJson/copy_fieldToArrayOfStringsWithIndex/expected.err
@@ -1,2 +1,2 @@
 ^Exception in thread "main" org\.metafacture\.metafix\.FixProcessException: Error while executing Fix expression \(at .*/metafix/src/test/resources/org/metafacture/metafix/integration/record/fromJson/toJson/copy_fieldToArrayOfStringsWithIndex/test\.fix, line 2\): copy_field\("key", "test\[\]\.1"\)$
-^Caused by: java\.lang\.IndexOutOfBoundsException: Index: 0, Size: 0$
+^Caused by: java\.lang\.IndexOutOfBoundsException: Index 0 out of bounds for length 0$