diff --git a/src/gui/kernel/qkeysequence.cpp b/src/gui/kernel/qkeysequence.cpp
index 5d6b817e74..8966287ad7 100644
--- a/src/gui/kernel/qkeysequence.cpp
+++ b/src/gui/kernel/qkeysequence.cpp
@@ -1203,10 +1203,10 @@ QString QKeySequencePrivate::encodeString(QKeyCombination keyCombination, QKeySe
     bool nativeText = (format == QKeySequence::NativeText);
     QString s;
 
-    int key = keyCombination.toCombined();
+    const auto key = keyCombination.key();
 
     // Handle -1 (Invalid Key) and Qt::Key_unknown gracefully
-    if (key == -1 || key == Qt::Key_unknown)
+    if (keyCombination.toCombined() == -1 || key == Qt::Key_unknown)
         return s;
 
     const auto modifiers = keyCombination.keyboardModifiers();
@@ -1253,7 +1253,7 @@ QString QKeySequencePrivate::encodeString(QKeyCombination keyCombination, QKeySe
     if (modifiers & Qt::KeypadModifier)
         addKey(s, nativeText ? QCoreApplication::translate("QShortcut", "Num") : QString::fromLatin1("Num"), format);
 
-    QString keyName = QKeySequencePrivate::keyName(keyCombination.key(), format);
+    QString keyName = QKeySequencePrivate::keyName(key, format);
 
 #if defined(Q_OS_APPLE)
     if (nativeText)
diff --git a/tests/auto/gui/kernel/qkeysequence/tst_qkeysequence.cpp b/tests/auto/gui/kernel/qkeysequence/tst_qkeysequence.cpp
index 976e4f76bb..bdfb14db10 100644
--- a/tests/auto/gui/kernel/qkeysequence/tst_qkeysequence.cpp
+++ b/tests/auto/gui/kernel/qkeysequence/tst_qkeysequence.cpp
@@ -473,6 +473,7 @@ void tst_QKeySequence::toStringFromKeycode_data()
     QTest::newRow("A") << QKeySequence(Qt::Key_A) << "A";
     QTest::newRow("-1") << QKeySequence(-1) << "";
     QTest::newRow("Unknown") << QKeySequence(Qt::Key_unknown) << "";
+    QTest::newRow("Ctrl+Unknown") << QKeySequence(Qt::ControlModifier | Qt::Key_unknown) << "";
     QTest::newRow("Ctrl+Num+Ins") << QKeySequence(Qt::ControlModifier | Qt::KeypadModifier | Qt::Key_Insert) << "Ctrl+Num+Ins";
     QTest::newRow("Ctrl+Num+Del") << QKeySequence(Qt::ControlModifier | Qt::KeypadModifier | Qt::Key_Delete) << "Ctrl+Num+Del";
     QTest::newRow("Ctrl+Alt+Num+Del") << QKeySequence(Qt::ControlModifier | Qt::AltModifier | Qt::KeypadModifier | Qt::Key_Delete) << "Ctrl+Alt+Num+Del";