diff --git a/autotests/integration/transient_placement.cpp b/autotests/integration/transient_placement.cpp
index a0aa9417d5..7a4e1b388d 100644
--- a/autotests/integration/transient_placement.cpp
+++ b/autotests/integration/transient_placement.cpp
@@ -209,6 +209,27 @@ void TransientPlacementTest::testXdgPopup_data()
     positioner.setGravity(Qt::TopEdge);
     positioner.setInitialSize(QSize(300, 200));
     QTest::newRow("constraintFlipRightNoGravity") << QSize(500, 500) << QPoint(700, 80) << positioner << QRect(700 + 50 - 150, 130, 300, 200);
+
+    // ----------------------------------------------------------------
+    // resize
+    positioner.setConstraints(XdgPositioner::Constraint::ResizeX | XdgPositioner::Constraint::ResizeY);
+    positioner.setInitialSize(QSize(200, 200));
+
+    positioner.setAnchorEdge(Qt::TopEdge);
+    positioner.setGravity(Qt::TopEdge);
+    QTest::newRow("resizeTop") << QSize(500, 500) << QPoint(80, 80) << positioner << QRect(80 + 250 - 100, 0, 200, 130);
+
+    positioner.setAnchorEdge(Qt::LeftEdge);
+    positioner.setGravity(Qt::LeftEdge);
+    QTest::newRow("resizeLeft") << QSize(500, 500) << QPoint(80, 80) << positioner << QRect(0, 80 + 250 - 100, 130, 200);
+
+    positioner.setAnchorEdge(Qt::RightEdge);
+    positioner.setGravity(Qt::RightEdge);
+    QTest::newRow("resizeRight") << QSize(500, 500) << QPoint(700, 80) << positioner << QRect(700 + 50 + 400, 80 + 250 - 100, 130, 200);
+
+    positioner.setAnchorEdge(Qt::BottomEdge);
+    positioner.setGravity(Qt::BottomEdge);
+    QTest::newRow("resizeBottom") << QSize(500, 500) << QPoint(80, 500) << positioner << QRect(80 + 250 - 100, 500 + 50 + 400, 200, 74);
 }
 
 void TransientPlacementTest::testXdgPopup()
@@ -249,7 +270,7 @@ void TransientPlacementTest::testXdgPopup()
     QCOMPARE(configureRequestedSpy.first()[0].value<QRect>(), expectedRelativeGeometry);
     popup->ackConfigure(configureRequestedSpy.first()[1].toUInt());
 
-    auto transient = Test::renderAndWaitForShown(transientSurface, positioner.initialSize(), Qt::red);
+    auto transient = Test::renderAndWaitForShown(transientSurface, expectedRelativeGeometry.size(), Qt::red);
     QVERIFY(transient);
 
     QVERIFY(!transient->isDecorated());
diff --git a/xdgshellclient.cpp b/xdgshellclient.cpp
index 1e3ca9458c..28788b3e8d 100644
--- a/xdgshellclient.cpp
+++ b/xdgshellclient.cpp
@@ -1712,8 +1712,18 @@ QRect XdgShellClient::transientPlacement(const QRect &bounds) const
         }
     }
     if (constraintAdjustments & PositionerConstraint::ResizeX) {
-        //TODO
-        //but we need to sort out when this is run as resize should only happen before first configure
+        QRect unconstrainedRect = popupPosition;
+
+        if (!inBounds(unconstrainedRect, Qt::LeftEdge)) {
+            unconstrainedRect.setLeft(bounds.left());
+        }
+        if (!inBounds(unconstrainedRect, Qt::RightEdge)) {
+            unconstrainedRect.setRight(bounds.right());
+        }
+
+        if (unconstrainedRect.isValid()) {
+            popupPosition = unconstrainedRect;
+        }
     }
 
     if (constraintAdjustments & PositionerConstraint::FlipY) {
@@ -1744,7 +1754,18 @@ QRect XdgShellClient::transientPlacement(const QRect &bounds) const
         }
     }
     if (constraintAdjustments & PositionerConstraint::ResizeY) {
-        //TODO
+        QRect unconstrainedRect = popupPosition;
+
+        if (!inBounds(unconstrainedRect, Qt::TopEdge)) {
+            unconstrainedRect.setTop(bounds.top());
+        }
+        if (!inBounds(unconstrainedRect, Qt::BottomEdge)) {
+            unconstrainedRect.setBottom(bounds.bottom());
+        }
+
+        if (unconstrainedRect.isValid()) {
+            popupPosition = unconstrainedRect;
+        }
     }
 
     return popupPosition;