diff --git a/mozilla/content/html/content/src/nsHTMLAtomList.h b/mozilla/content/html/content/src/nsHTMLAtomList.h
index cf06d93f085..e41da7630db 100644
--- a/mozilla/content/html/content/src/nsHTMLAtomList.h
+++ b/mozilla/content/html/content/src/nsHTMLAtomList.h
@@ -184,6 +184,7 @@ HTML_ATOM(leftpadding, "leftpadding")
 HTML_ATOM(legend, "legend")
 HTML_ATOM(length, "length")
 HTML_ATOM(longdesc, "longdesc")
+HTML_ATOM(lowsrc, "lowsrc")
 HTML_ATOM(map, "map")
 HTML_ATOM(marginheight, "marginheight")
 HTML_ATOM(marginwidth, "marginwidth")
diff --git a/mozilla/content/html/content/src/nsHTMLImageElement.cpp b/mozilla/content/html/content/src/nsHTMLImageElement.cpp
index f79a9bd4b5a..8b76fb6cb3f 100644
--- a/mozilla/content/html/content/src/nsHTMLImageElement.cpp
+++ b/mozilla/content/html/content/src/nsHTMLImageElement.cpp
@@ -258,6 +258,7 @@ NS_IMPL_STRING_ATTR(nsHTMLImageElement, Border, border)
 NS_IMPL_PIXEL_ATTR(nsHTMLImageElement, Hspace, hspace)
 NS_IMPL_BOOL_ATTR(nsHTMLImageElement, IsMap, ismap)
 NS_IMPL_STRING_ATTR(nsHTMLImageElement, LongDesc, longdesc)
+NS_IMPL_STRING_ATTR(nsHTMLImageElement, Lowsrc, lowsrc)
 NS_IMPL_STRING_ATTR(nsHTMLImageElement, UseMap, usemap)
 NS_IMPL_PIXEL_ATTR(nsHTMLImageElement, Vspace, vspace)
 
diff --git a/mozilla/content/shared/public/nsHTMLAtomList.h b/mozilla/content/shared/public/nsHTMLAtomList.h
index cf06d93f085..e41da7630db 100644
--- a/mozilla/content/shared/public/nsHTMLAtomList.h
+++ b/mozilla/content/shared/public/nsHTMLAtomList.h
@@ -184,6 +184,7 @@ HTML_ATOM(leftpadding, "leftpadding")
 HTML_ATOM(legend, "legend")
 HTML_ATOM(length, "length")
 HTML_ATOM(longdesc, "longdesc")
+HTML_ATOM(lowsrc, "lowsrc")
 HTML_ATOM(map, "map")
 HTML_ATOM(marginheight, "marginheight")
 HTML_ATOM(marginwidth, "marginwidth")
diff --git a/mozilla/dom/public/idl/html/nsIDOMNSHTMLImageElement.idl b/mozilla/dom/public/idl/html/nsIDOMNSHTMLImageElement.idl
index 469e4926f76..fca44440568 100644
--- a/mozilla/dom/public/idl/html/nsIDOMNSHTMLImageElement.idl
+++ b/mozilla/dom/public/idl/html/nsIDOMNSHTMLImageElement.idl
@@ -43,6 +43,7 @@
 [scriptable, uuid(a6cf90c7-15b3-11d2-932e-00805f8add32)]
 interface nsIDOMNSHTMLImageElement : nsISupports
 {
+           attribute DOMString        lowsrc;
   readonly attribute boolean          complete;
 
   readonly attribute long             naturalHeight;