diff --git a/src/corelib/tools/qvarlengtharray.h b/src/corelib/tools/qvarlengtharray.h
index 4d2e80548d5..4bff61b9b68 100644
--- a/src/corelib/tools/qvarlengtharray.h
+++ b/src/corelib/tools/qvarlengtharray.h
@@ -648,7 +648,7 @@ Q_OUTOFLINE_TEMPLATE auto QVarLengthArray<T, Prealloc>::emplace(const_iterator b
 }
 
 template <class T, qsizetype Prealloc>
-Q_OUTOFLINE_TEMPLATE typename QVarLengthArray<T, Prealloc>::iterator QVarLengthArray<T, Prealloc>::insert(const_iterator before, size_type n, const T &t)
+Q_OUTOFLINE_TEMPLATE typename QVarLengthArray<T, Prealloc>::iterator QVarLengthArray<T, Prealloc>::insert(const_iterator before, qsizetype n, const T &t)
 {
     Q_ASSERT_X(isValidIterator(before), "QVarLengthArray::insert", "The specified const_iterator argument 'before' is invalid");