           @viewBox[3] = zeroSizeReplacement
       ## Reset viewBox attribute in case either absent (and computed via
       ## svgBBox) or changed to avoid zeroes.
-      @xml.documentElement.setAttribute 'viewBox', @viewBox.join ' '
-    @overflowBox = extractOverflowBox @xml
+      @dom.documentElement.setAttribute 'viewBox', @viewBox.join ' '
+    @overflowBox = extractOverflowBox @dom
     @width = forceWidth if (forceWidth = @getSetting 'forceWidth')?
     @height = forceHeight if (forceHeight = @getSetting 'forceHeight')?
     warnings = []

        true

    ## Compute viewBox attribute if absent.
    @viewBox = svgBBox @xml

    ## Overflow behavior
    overflow = attributeOrStyle @xml.documentElement, 'overflow'
    if not overflow? and (overflowDefault = @getSetting 'overflowDefault')?
      @xml.documentElement.setAttribute 'overflow',
        overflow = overflowDefault
    @overflowVisible = (overflow? and /^\s*(visible|scroll)\b/.test overflow)
    @width = @height = null

          ## Include new <symbol> in SVG
          unless found?
            tile.setId @id key unless tile.id?  # unrecognizedTile has id
            svg.appendChild tile.makeDOM().documentElement
            if symbolIds.has tile.id
              console.warn "Multiple symbols with id '#{tile.id}': This shouldn't happen, and SVG likely won't load correctly."
            else
