diff --git a/artiq/gui/dndwidgets.py b/artiq/gui/dndwidgets.py
index 43cc20d4b..46572e57c 100644
--- a/artiq/gui/dndwidgets.py
+++ b/artiq/gui/dndwidgets.py
@@ -59,7 +59,6 @@ class DragDropSplitter(QtWidgets.QSplitter):
 class VDragScrollArea(QtWidgets.QScrollArea):
     def __init__(self, parent):
         QtWidgets.QScrollArea.__init__(self, parent)
-        self.setVerticalScrollBarPolicy(QtCore.Qt.ScrollBarAlwaysOff)
         self.installEventFilter(self)
         self._margin = 40
         self._timer = QtCore.QTimer(self)
@@ -68,31 +67,32 @@ class VDragScrollArea(QtWidgets.QScrollArea):
         self._direction = 0
         self._speed = 10
 
+    def setAutoScrollMargin(self, margin):
+        self._margin = margin
+
+    def setAutoScrollSpeed(self, speed):
+        self._speed = speed
+
     def eventFilter(self, obj, e):
         if e.type() == QtCore.QEvent.DragMove:
             val = self.verticalScrollBar().value()
-            vp_height = self.viewport().height()
-            pos = e.pos()
-            if pos.y() < val + self._margin:
+            height = self.viewport().height()
+            y = e.pos().y()
+            self._direction = 0
+            if y < val + self._margin:
                 self._direction = -1
-            elif pos.y() > vp_height + val - self._margin:
+            elif y > height + val - self._margin:
                 self._direction = 1
-            else:
-                self._direction = 0
             if not self._timer.isActive():
                 self._timer.start()
         elif e.type() in (QtCore.QEvent.Drop, QtCore.QEvent.DragLeave):
             self._timer.stop()
         return False
 
-    def setAutoScrollMargin(self, margin):
-        self._margin = margin
-
     def _on_auto_scroll(self):
         val = self.verticalScrollBar().value()
-        mini = self.verticalScrollBar().minimum()
-        maxi = self.verticalScrollBar().maximum()
-        dx = self._direction * self._speed
-        new_val = min(maxi, max(mini, val + dx))
+        mn = self.verticalScrollBar().minimum()
+        mx = self.verticalScrollBar().maximum()
+        dy = self._direction * self._speed
+        new_val = min(mx, max(mn, val + dy))
         self.verticalScrollBar().setValue(new_val)
-