diff --git a/mozilla/layout/base/nsLayoutAtomList.h b/mozilla/layout/base/nsLayoutAtomList.h
index c8293801757..05c7ea450f2 100644
--- a/mozilla/layout/base/nsLayoutAtomList.h
+++ b/mozilla/layout/base/nsLayoutAtomList.h
@@ -195,6 +195,7 @@ LAYOUT_ATOM(onresize, "onresize")
 LAYOUT_ATOM(onscroll, "onscroll")
 LAYOUT_ATOM(onselect, "onselect")
 LAYOUT_ATOM(onsubmit, "onsubmit")
+LAYOUT_ATOM(ontext, "ontext")
 LAYOUT_ATOM(onunload, "onunload")
 
 // scrolling