diff --git a/widget/PuppetWidget.cpp b/widget/PuppetWidget.cpp
index 6b0ac0d580f0..c47151485a94 100644
--- a/widget/PuppetWidget.cpp
+++ b/widget/PuppetWidget.cpp
@@ -1434,6 +1434,7 @@ PuppetWidget::HasPendingInputEvent()
           case mozilla::dom::PBrowser::Msg_UpdateDimensions__ID:
           case mozilla::dom::PBrowser::Msg_MouseEvent__ID:
           case mozilla::dom::PBrowser::Msg_KeyEvent__ID:
+          case mozilla::dom::PBrowser::Msg_SetDocShellIsActive__ID:
             ret = true;
             return false;  // Stop peeking.
         }