diff --git a/content/base/src/nsGenericElement.cpp b/content/base/src/nsGenericElement.cpp
index 097ce8c2a4b3..f2d760927c84 100644
--- a/content/base/src/nsGenericElement.cpp
+++ b/content/base/src/nsGenericElement.cpp
@@ -3615,7 +3615,7 @@ nsGenericElement::DispatchClickEvent(nsPresContext* aPresContext,
   event.isControl = aSourceEvent->isControl;
   event.isAlt = aSourceEvent->isAlt;
   event.isMeta = aSourceEvent->isMeta;
-  event.flags = aFlags;
+  event.flags |= aFlags; // Be careful not to overwrite existing flags!
 
   return DispatchEvent(aPresContext, &event, aTarget, aFullDispatch, aStatus);
 }