diff --git a/src/lib/repository.h b/src/lib/repository.h
--- a/src/lib/repository.h
+++ b/src/lib/repository.h
@@ -167,7 +167,7 @@
     Definition definitionForFileName(const QString &fileName) const;
 
     /**
-     * Returns all Definition%s for the file named @p fileName.
+     * Returns all Definition%s for the file named @p fileName sorted by priority.
      * The match is performed based on the \e extensions and @e mimetype of
      * the definition files.
      *
@@ -186,7 +186,7 @@
     Definition definitionForMimeType(const QString &mimeType) const;
 
     /**
-     * Returns all Definition%s to the type named @p mimeType
+     * Returns all Definition%s to the type named @p mimeType sorted by priority
      *
      * @since 5.56
      */
diff --git a/src/lib/repository.cpp b/src/lib/repository.cpp
--- a/src/lib/repository.cpp
+++ b/src/lib/repository.cpp
@@ -78,59 +78,55 @@
     return d->m_defs.value(defName);
 }
 
-static Definition bestCandidate(QVector<Definition> &&candidates)
+static void sortDefinitions(QVector<Definition> &definitions)
 {
-    if (candidates.isEmpty())
-        return Definition();
-
-    std::partial_sort(candidates.begin(), candidates.begin() + 1, candidates.end(), [](const Definition &lhs, const Definition &rhs) {
+    std::stable_sort(definitions.begin(), definitions.end(), [](const Definition &lhs, const Definition &rhs) {
         return lhs.priority() > rhs.priority();
     });
-
-    return candidates.at(0);
 }
 
 Definition Repository::definitionForFileName(const QString& fileName) const
 {
-    return bestCandidate(definitionsForFileName(fileName));
+    return definitionsForFileName(fileName).value(0);
 }
 
 QVector<Definition> Repository::definitionsForFileName(const QString &fileName) const
 {
     QFileInfo fi(fileName);
     const auto name = fi.fileName();
 
     QVector<Definition> candidates;
-    for (auto it = d->m_defs.constBegin(); it != d->m_defs.constEnd(); ++it) {
-        auto def = it.value();
+    for (const Definition &def : qAsConst(d->m_sortedDefs)) {
         for (const auto &pattern : def.extensions()) {
             if (WildcardMatcher::exactMatch(name, pattern)) {
                 candidates.push_back(def);
                 break;
             }
         }
     }
 
+    sortDefinitions(candidates);
     return candidates;
 }
 
 Definition Repository::definitionForMimeType(const QString& mimeType) const
 {
-    return bestCandidate(definitionsForMimeType(mimeType));
+    return definitionsForMimeType(mimeType).value(0);
 }
 
 QVector<Definition> Repository::definitionsForMimeType(const QString &mimeType) const
 {
     QVector<Definition> candidates;
-    for (auto it = d->m_defs.constBegin(); it != d->m_defs.constEnd(); ++it) {
-        auto def = it.value();
+    for (const Definition &def : qAsConst(d->m_sortedDefs)) {
         for (const auto &matchType : def.mimeTypes()) {
             if (mimeType == matchType) {
                 candidates.push_back(def);
                 break;
             }
         }
     }
+
+    sortDefinitions(candidates);
     return candidates;
 }