http://www.nabble.com/expressions-conflict-with-property-placeholder-td19637042.html#a19650222 Following the idea of 'fewer surprises', we may consider changing Mule's default property placeholder prefix. Currently it uses ${}. The problem is Spring, which also uses ${}, or rather its PropertyPlaceholderConfigurer. It leads to variables not being resolved at config/runtime. The current workaround is switching Spring's PPC to something else, but that means we're intruding into existing Spring apps, which is contrary to Mule's philosophy. Maybe we can get away with some transition period, when the new syntax support is enabled by a system variable or the like.