diff --git a/scour/scour.py b/scour/scour.py
index 31cf1e7..4a2c1b3 100644
--- a/scour/scour.py
+++ b/scour/scour.py
@@ -3000,6 +3000,9 @@ def serializeXML(element, options, ind = 0, preserveWhitespace = False):
          quot = "'"
 
       attrValue = makeWellFormed( attr.nodeValue )
+      if attr.nodeName == 'style':
+          # sort declarations
+          attrValue = '; '.join([p for p in sorted(attrValue.split(';'))])
 
       outParts.append(' ')
       # preserve xmlns: if it is a namespace prefix declaration