diff --git a/src/widgets/widgets/qmdiarea.cpp b/src/widgets/widgets/qmdiarea.cpp
index 3ab8632f805..1167524a0aa 100644
--- a/src/widgets/widgets/qmdiarea.cpp
+++ b/src/widgets/widgets/qmdiarea.cpp
@@ -2318,7 +2318,14 @@ void QMdiArea::resizeEvent(QResizeEvent *resizeEvent)
     foreach (QMdiSubWindow *child, d->childWindows) {
         if (sanityCheck(child, "QMdiArea::resizeEvent") && child->isMaximized()
                 && child->size() != resizeEvent->size()) {
-            child->resize(resizeEvent->size());
+            auto realSize = resizeEvent->size();
+            const auto minSizeHint = child->minimumSizeHint();
+            // QMdiSubWindow is no tlw so minimumSize() is not set by the layout manager
+            // and therefore we have to take care by ourself that we're not getting smaller
+            // than allowed
+            if (minSizeHint.isValid())
+                realSize = realSize.expandedTo(minSizeHint);
+            child->resize(realSize);
             if (!hasMaximizedSubWindow)
                 hasMaximizedSubWindow = true;
         }
diff --git a/tests/auto/widgets/widgets/qmdisubwindow/tst_qmdisubwindow.cpp b/tests/auto/widgets/widgets/qmdisubwindow/tst_qmdisubwindow.cpp
index b19fb3f9899..9c51b3c8a45 100644
--- a/tests/auto/widgets/widgets/qmdisubwindow/tst_qmdisubwindow.cpp
+++ b/tests/auto/widgets/widgets/qmdisubwindow/tst_qmdisubwindow.cpp
@@ -45,6 +45,7 @@
 #include <QStyleOptionTitleBar>
 #include <QPushButton>
 #include <QScreen>
+#include <QScrollBar>
 #include <QSizeGrip>
 #include <QSignalSpy>
 #include <QList>
@@ -221,6 +222,7 @@ private slots:
     void styleChange();
     void testFullScreenState();
     void testRemoveBaseWidget();
+    void testRespectMinimumSize();
 };
 
 void tst_QMdiSubWindow::initTestCase()
@@ -2163,6 +2165,36 @@ void tst_QMdiSubWindow::testRemoveBaseWidget()
     delete widget1;
 }
 
+void tst_QMdiSubWindow::testRespectMinimumSize()  // QTBUG-100494
+{
+    QMdiArea mdiArea;
+    mdiArea.resize(400, 400);
+    mdiArea.setHorizontalScrollBarPolicy(Qt::ScrollBarAsNeeded);
+    mdiArea.setVerticalScrollBarPolicy(Qt::ScrollBarAsNeeded);
+
+    auto vlay = new QVBoxLayout;
+    vlay->addWidget(new QPushButton(QLatin1String("btn1-1")));
+    vlay->addSpacerItem(new QSpacerItem(20, 40, QSizePolicy::Minimum, QSizePolicy::Expanding));
+    vlay->addWidget(new QPushButton(QLatin1String("btn1-2")));
+    auto w1 = new QWidget;
+    w1->setLayout(vlay);
+    w1->resize(300, 200);
+    w1->setMinimumSize(200, 150);
+    auto sw = new QMdiSubWindow;
+    sw->setWidget(w1);
+    sw->resize(w1->size());
+    mdiArea.addSubWindow(sw);
+    sw->showMaximized();
+
+    mdiArea.show();
+    QVERIFY(QTest::qWaitForWindowExposed(&mdiArea));
+    QVERIFY(!mdiArea.horizontalScrollBar()->isVisible());
+    QVERIFY(!mdiArea.verticalScrollBar()->isVisible());
+    mdiArea.resize(150, 100);
+    QTRY_VERIFY(mdiArea.horizontalScrollBar()->isVisible());
+    QTRY_VERIFY(mdiArea.verticalScrollBar()->isVisible());
+}
+
 QTEST_MAIN(tst_QMdiSubWindow)
 #include "tst_qmdisubwindow.moc"