diff --git a/sources/PropertiesEditor/propertieseditordockwidget.ui b/sources/PropertiesEditor/propertieseditordockwidget.ui
index 9f58f52bf..c98821006 100644
--- a/sources/PropertiesEditor/propertieseditordockwidget.ui
+++ b/sources/PropertiesEditor/propertieseditordockwidget.ui
@@ -16,7 +16,7 @@
   <widget class="QWidget" name="dockWidgetContents">
    <layout class="QVBoxLayout" name="verticalLayout">
     <property name="sizeConstraint">
-     <enum>QLayout::SetMaximumSize</enum>
+     <enum>QLayout::SetDefaultConstraint</enum>
     </property>
     <property name="leftMargin">
      <number>0</number>
diff --git a/tests/qttest/CMakeLists.txt b/tests/qttest/CMakeLists.txt
index 840341d3d..6ca55e8ca 100644
--- a/tests/qttest/CMakeLists.txt
+++ b/tests/qttest/CMakeLists.txt
@@ -279,6 +279,10 @@ qet_add_app_test(tst_imagehandleescape tst_imagehandleescape.cpp)
 # pixels and position; an <image> with no picture does not stop the others.
 qet_add_app_test(tst_folioimageload tst_folioimageload.cpp)
 
+# The Selection properties panel keeps the height the user gave it when the
+# selection has nothing to edit for a moment (#1439).
+qet_add_app_test(tst_selectionpanelheight tst_selectionpanelheight.cpp)
+
 # SVG export with smaller pictures (--svg-small-pictures, the export dialog's
 # option): a picture drawn at a tenth of its size is stored at four times
 # that, a small one whole; without the option every picture is whole.
diff --git a/tests/qttest/tst_selectionpanelheight.cpp b/tests/qttest/tst_selectionpanelheight.cpp
new file mode 100644
index 000000000..49ccb1024
--- /dev/null
+++ b/tests/qttest/tst_selectionpanelheight.cpp
@@ -0,0 +1,69 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+#include "qetapptest.h"
+
+#include "projectview.h"
+#include "qetgraphicsitem/element.h"
+
+#include <QDockWidget>
+
+// The Selection properties panel keeps the height the user gave it when the
+// selection has nothing it can edit for a moment (#1439). It used to shrink
+// to its title bar, the other panels took the room, and an element selected
+// again brought the panel back at its default height.
+class tst_selectionpanelheight : public QObject
+{
+	Q_OBJECT
+
+	QTemporaryDir m_dir;
+
+	private slots:
+		void keepsUserHeight()
+		{
+			QETDiagramEditor *editor = QetAppTest::editor();
+			QVERIFY(editor);
+				// Tall enough to leave the panels room to be resized: at a
+				// usual height every right-hand panel is at its minimum
+			editor->resize(1600, 1500);
+			editor->show();
+			QVERIFY(QTest::qWaitForWindowExposed(editor));
+
+				// A copy: opening a project leaves a lock file beside it
+			const QString copy = m_dir.filePath("p.qet");
+			QVERIFY(QFile::copy(QFINDTESTDATA("fixtures/ten_sequential_numbers.qet"), copy));
+			QVERIFY(editor->openAndAddProject(copy, false));
+			Diagram *diagram = editor->currentProjectView()->currentDiagram()->diagram();
+			Element *element = nullptr;
+			for (QGraphicsItem *qgi : diagram->items())
+				if (qgi->type() == Element::Type)
+					element = static_cast<Element *>(qgi);
+			QVERIFY(element);
+
+			auto panel = editor->findChild<QDockWidget *>("diagram_properties_editor_dock_widget");
+			QVERIFY(panel);
+
+				// The panel follows the selection through a queued connection
+			auto select = [&](Element *e) {
+				diagram->clearSelection();
+				if (e)
+					e->setSelected(true);
+				QTest::qWait(200);
+			};
+
+			select(element);
+			const int start = panel->height();
+				// What dragging the separator above the panel does
+			editor->resizeDocks({panel}, {start + 150}, Qt::Vertical);
+			QTest::qWait(200);
+			const int user = panel->height();
+			QVERIFY2(user > start, "the panel could not be made taller");
+
+			select(nullptr);
+			QCOMPARE(panel->height(), user);
+			select(element);
+			QCOMPARE(panel->height(), user);
+		}
+};
+
+QET_APP_TEST_MAIN(tst_selectionpanelheight)
+
+#include "tst_selectionpanelheight.moc"