diff --git a/src/pyj/read_book/iframe.pyj b/src/pyj/read_book/iframe.pyj
index 057d8193e2..48a827b295 100644
--- a/src/pyj/read_book/iframe.pyj
+++ b/src/pyj/read_book/iframe.pyj
@@ -583,6 +583,8 @@ class IframeBoss:
     def onmouseup(self, evt):
         cancel_drag_scroll()
         drag_mouse_position.x = drag_mouse_position.y = None
+        # ensure selection bar is updated
+        self.onselectionchange()
 
     def onkeydown(self, evt):
         if current_layout_mode() is not 'flow' and evt.key is 'Tab':
diff --git a/src/pyj/read_book/selection_bar.pyj b/src/pyj/read_book/selection_bar.pyj
index 71296f4b75..579174ca05 100644
--- a/src/pyj/read_book/selection_bar.pyj
+++ b/src/pyj/read_book/selection_bar.pyj
@@ -171,7 +171,7 @@ class SelectionBar:
         container = self.container
         clear(container)
         cs = self.view.currently_showing.selection
-        if not cs or cs.empty:
+        if not cs or cs.empty or jstype(cs.drag_mouse_position.x) is 'number':
             return self.hide()
 
         if not cs.start.onscreen and not cs.end.onscreen: