diff --git a/dom/svg/nsSVGElement.cpp b/dom/svg/nsSVGElement.cpp
index 9698617042..77dbcb939d 100644
--- a/dom/svg/nsSVGElement.cpp
+++ b/dom/svg/nsSVGElement.cpp
@@ -1268,24 +1268,6 @@ nsSVGElement::UpdateContentStyleRule()
       continue; // xml:lang has precedence
     }
 
-    if (IsSVGElement(nsGkAtoms::svg)) {
-      // Special case: we don't want <svg> 'width'/'height' mapped into style
-      // if the attribute value isn't a valid <length> according to SVG (which
-      // only supports a subset of the CSS <length> values). We don't enforce
-      // this by checking the attribute value in SVGSVGElement::
-      // IsAttributeMapped since we don't want that method to depend on the
-      // value of the attribute that is being checked. Rather we just prevent
-      // the actual mapping here, as necessary.
-      if (attrName->Atom() == nsGkAtoms::width &&
-          !GetAnimatedLength(nsGkAtoms::width)->HasBaseVal()) {
-        continue;
-      }
-      if (attrName->Atom() == nsGkAtoms::height &&
-          !GetAnimatedLength(nsGkAtoms::height)->HasBaseVal()) {
-        continue;
-      }
-    }
-
     nsAutoString value;
     mAttrsAndChildren.AttrAt(i)->ToString(value);
     mappedAttrParser.ParseMappedAttrValue(attrName->Atom(), value);