diff --git a/src/corelib/serialization/qcborstreamreader.cpp b/src/corelib/serialization/qcborstreamreader.cpp
index 493d1b94caa..c8ea1fbe6cd 100644
--- a/src/corelib/serialization/qcborstreamreader.cpp
+++ b/src/corelib/serialization/qcborstreamreader.cpp
@@ -574,7 +574,7 @@ public:
     char *bufferPtr()
     {
         Q_ASSERT(buffer.isDetached());
-        return const_cast<char *>(buffer.constData()) + bufferStart;
+        return const_cast<char *>(buffer.constBegin()) + bufferStart;
     }
 
     void preread()
@@ -671,7 +671,7 @@ static void *qt_cbor_decoder_read(void *token, void *userptr, size_t offset, siz
 
     // we must have pre-read the data
     Q_ASSERT(len + offset <= size_t(self->buffer.size() - self->bufferStart));
-    return memcpy(userptr, self->buffer.constData() + self->bufferStart + offset, len);
+    return memcpy(userptr, self->buffer.constBegin() + self->bufferStart + offset, len);
 }
 
 static CborError qt_cbor_decoder_transfer_string(void *token, const void **userptr, size_t offset, size_t len)
@@ -840,7 +840,7 @@ QIODevice *QCborStreamReader::device() const
  */
 void QCborStreamReader::addData(const QByteArray &data)
 {
-    addData(data.constData(), data.size());
+    addData(data.constBegin(), data.size());
 }
 
 /*!
@@ -1752,7 +1752,7 @@ QCborStreamReaderPrivate::readStringChunk_byte(ReadStringChunk params, qsizetype
             return -1;
         }
 
-        ptr = const_cast<char *>(params.array->constData()) + oldSize;
+        ptr = const_cast<char *>(params.array->constBegin()) + oldSize;
     }
 
     if (device) {
@@ -1772,7 +1772,7 @@ QCborStreamReaderPrivate::readStringChunk_byte(ReadStringChunk params, qsizetype
         }
     } else {
         actuallyRead = toRead;
-        memcpy(ptr, buffer.constData() + bufferStart, toRead);
+        memcpy(ptr, buffer.constBegin() + bufferStart, toRead);
     }
 
     return actuallyRead;
@@ -1798,12 +1798,12 @@ QCborStreamReaderPrivate::readStringChunk_unicode(ReadStringChunk params, qsizet
         return -1;
     }
 
-    QChar *begin = const_cast<QChar *>(params.string->constData());
+    QChar *begin = const_cast<QChar *>(params.string->constBegin());
     QChar *ptr = begin + currentSize;
     QStringConverter::State cs(QStringConverter::Flag::Stateless);
     if (device == nullptr) {
         // Easy case: we can decode straight from the buffer we already have
-        ptr = QUtf8::convertToUnicode(ptr, { buffer.constData() + bufferStart, utf8len }, &cs);
+        ptr = QUtf8::convertToUnicode(ptr, { buffer.constBegin() + bufferStart, utf8len }, &cs);
     } else {
         // read in chunks, to avoid creating large, intermediate buffers
         constexpr qsizetype StringChunkSize = 16384;