diff --git a/autotests/syntaxrepository_test.cpp b/autotests/syntaxrepository_test.cpp
--- a/autotests/syntaxrepository_test.cpp
+++ b/autotests/syntaxrepository_test.cpp
@@ -162,16 +162,26 @@
         auto formats = def.formats();
         QVERIFY(!formats.isEmpty());
 
+        // verify that the formats are sorted, such that the order matches the order of the itemDatas in the xml files.
+        auto sortComparator = [](const KSyntaxHighlighting::Format & lhs, const KSyntaxHighlighting::Format & rhs) {
+            return lhs.id() < rhs.id();
+        };
+        QVERIFY(std::is_sorted(formats.begin(), formats.end(), sortComparator));
+
+        // check all names are listed
         QStringList formatNames;
         foreach (const auto & format, formats) {
             formatNames.append(format.name());
         }
-        QVERIFY(formatNames.contains(QStringLiteral("Normal Text")));
-        QVERIFY(formatNames.contains(QStringLiteral("Name")));
-        QVERIFY(formatNames.contains(QStringLiteral("E-Mail")));
-        QVERIFY(formatNames.contains(QStringLiteral("Date")));
-        QVERIFY(formatNames.contains(QStringLiteral("Entry")));
-        QVERIFY(!formatNames.contains(QStringLiteral("Does not Exist")));
+
+        const QStringList expectedItemDatas = {
+            QStringLiteral("Normal Text"),
+            QStringLiteral("Name"),
+            QStringLiteral("E-Mail"),
+            QStringLiteral("Date"),
+            QStringLiteral("Entry")
+        };
+        QCOMPARE(formatNames, expectedItemDatas);
     }
 
     void testIncludedDefinitions()
diff --git a/src/lib/definition.h b/src/lib/definition.h
--- a/src/lib/definition.h
+++ b/src/lib/definition.h
@@ -188,6 +188,7 @@
 
     /**
      * Returns a list of all Format items used by this definition.
+     * The order of the Format items equals the order of the itemDatas in the xml file.
      * @since 5.49
      */
     QVector<Format> formats() const;
diff --git a/src/lib/definition.cpp b/src/lib/definition.cpp
--- a/src/lib/definition.cpp
+++ b/src/lib/definition.cpp
@@ -196,7 +196,14 @@
 QVector<Format> Definition::formats() const
 {
     d->load();
-    return QVector<Format>::fromList(d->formats.values());
+
+    // sort formats so that the order matches the order of the itemDatas in the xml files.
+    auto formatList = QVector<Format>::fromList(d->formats.values());
+    std::sort(formatList.begin(), formatList.end(), [](const KSyntaxHighlighting::Format & lhs, const KSyntaxHighlighting::Format & rhs){
+        return lhs.id() < rhs.id();
+    });
+
+    return formatList;
 }
 
 QVector<Definition> Definition::includedDefinitions() const