diff --git a/src/plasmaquick/dialog.cpp b/src/plasmaquick/dialog.cpp
--- a/src/plasmaquick/dialog.cpp
+++ b/src/plasmaquick/dialog.cpp
@@ -205,9 +205,13 @@
     QRect avail = availableScreenGeometryForPosition(geom.topLeft());
     int borders = Plasma::FrameSvg::AllBorders;
 
+    QWindow *parentWindow = q->transientParent();
+    bool inDock = parentWindow && !parentWindow->mask().isNull() && KWindowSystem::compositingActive();
+
     //Tooltips always have all the borders
     // floating windows have all borders
-    if (!q->flags().testFlag(Qt::ToolTip) && location != Plasma::Types::Floating) {
+    // popup windows from docks have all borders
+    if (!q->flags().testFlag(Qt::ToolTip) && location != Plasma::Types::Floating && !inDock) {
         if (geom.x() <= avail.x() || location == Plasma::Types::LeftEdge) {
             borders = borders & ~Plasma::FrameSvg::LeftBorder;
         }