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$