diff --git a/src/gui/kernel/qhighdpiscaling_p.h b/src/gui/kernel/qhighdpiscaling_p.h
index 60e8dcf562d..fe71de6c27d 100644
--- a/src/gui/kernel/qhighdpiscaling_p.h
+++ b/src/gui/kernel/qhighdpiscaling_p.h
@@ -473,6 +473,7 @@ QVector<T> fromNativePixels(const QVector<T> &pixelValues, const QWindow *window
         return pixelValues;
 
     QVector<T> pointValues;
+    pointValues.reserve(pixelValues.size());
     for (const T &pixelValue : pixelValues)
         pointValues.append(pixelValue / QHighDpiScaling::factor(window));
     return pointValues;
@@ -486,6 +487,7 @@ QVector<T> toNativePixels(const QVector<T> &pointValues, const QWindow *window)
         return pointValues;
 
     QVector<T> pixelValues;
+    pixelValues.reserve(pointValues.size());
     for (const T &pointValue : pointValues)
         pixelValues.append(pointValue * QHighDpiScaling::factor(window));
     return pixelValues;
diff --git a/src/gui/kernel/qwindowsysteminterface.cpp b/src/gui/kernel/qwindowsysteminterface.cpp
index c76721f89b5..39bc161a7c1 100644
--- a/src/gui/kernel/qwindowsysteminterface.cpp
+++ b/src/gui/kernel/qwindowsysteminterface.cpp
@@ -928,7 +928,7 @@ static QWindowSystemInterface::TouchPoint touchPoint(const QTouchEvent::TouchPoi
 static QList<struct QWindowSystemInterface::TouchPoint> touchPointList(const QList<QTouchEvent::TouchPoint>& pointList)
 {
     QList<struct QWindowSystemInterface::TouchPoint> newList;
-
+    newList.reserve(pointList.size());
     for (const QTouchEvent::TouchPoint &p : pointList)
         newList.append(touchPoint(p));
 
diff --git a/src/gui/text/qfontsubset.cpp b/src/gui/text/qfontsubset.cpp
index 34db39e4a8f..a9387e5aa09 100644
--- a/src/gui/text/qfontsubset.cpp
+++ b/src/gui/text/qfontsubset.cpp
@@ -624,6 +624,7 @@ static QTtfTable generateName(const QVector<QTtfNameRecord> &name);
 static QTtfTable generateName(const qttf_name_table &name)
 {
     QVector<QTtfNameRecord> list;
+    list.reserve(5);
     QTtfNameRecord rec;
     rec.nameId = 0;
     rec.value = name.copyright;
@@ -1061,6 +1062,7 @@ static QVector<QTtfTable> generateGlyphTables(qttf_font_tables &tables, const QV
     Q_ASSERT(hmtx.data.size() == hs.offset());
 
     QVector<QTtfTable> list;
+    list.reserve(3);
     list.append(glyf);
     list.append(loca);
     list.append(hmtx);