diff --git a/src/corelib/serialization/qcborvalue.cpp b/src/corelib/serialization/qcborvalue.cpp
index db2840704c..5a59646233 100644
--- a/src/corelib/serialization/qcborvalue.cpp
+++ b/src/corelib/serialization/qcborvalue.cpp
@@ -2506,7 +2506,7 @@ QCborValue QCborValue::fromCbor(const QByteArray &ba, QCborParserError *error)
 
     \sa fromCbor(), fromVariant(), fromJsonValue()
  */
-QByteArray QCborValue::toCbor(EncodingOptions opt)
+QByteArray QCborValue::toCbor(EncodingOptions opt) const
 {
     QByteArray result;
     QCborStreamWriter writer(&result);
@@ -2543,7 +2543,7 @@ QByteArray QCborValue::toCbor(EncodingOptions opt)
 
     \sa fromCbor(), fromVariant(), fromJsonValue()
  */
-Q_NEVER_INLINE void QCborValue::toCbor(QCborStreamWriter &writer, EncodingOptions opt)
+Q_NEVER_INLINE void QCborValue::toCbor(QCborStreamWriter &writer, EncodingOptions opt) const
 {
     if (isContainer() || isTag())
         return encodeToCbor(writer, container, -type(), opt);
diff --git a/src/corelib/serialization/qcborvalue.h b/src/corelib/serialization/qcborvalue.h
index f7064ac6e1..bbe2774e69 100644
--- a/src/corelib/serialization/qcborvalue.h
+++ b/src/corelib/serialization/qcborvalue.h
@@ -298,8 +298,8 @@ public:
     { return fromCbor(QByteArray(reinterpret_cast<const char *>(data), int(len)), error); }
 #endif // QT_CONFIG(cborstreamreader)
 #if QT_CONFIG(cborstreamwriter)
-    QByteArray toCbor(EncodingOptions opt = NoTransformation);
-    void toCbor(QCborStreamWriter &writer, EncodingOptions opt = NoTransformation);
+    QByteArray toCbor(EncodingOptions opt = NoTransformation) const;
+    void toCbor(QCborStreamWriter &writer, EncodingOptions opt = NoTransformation) const;
 #endif
 
     QString toDiagnosticNotation(DiagnosticNotationOptions opts = Compact) const;