diff --git a/dust/src/main/scala/com/typesafe/plugin/DustTasks.scala b/dust/src/main/scala/com/typesafe/plugin/DustTasks.scala
index ce1f04d..151bfb0 100644
--- a/dust/src/main/scala/com/typesafe/plugin/DustTasks.scala
+++ b/dust/src/main/scala/com/typesafe/plugin/DustTasks.scala
@@ -70,7 +70,7 @@ trait DustTasks extends DustKeys {
 
         val generated = (files x relativeTo(assetsDir)).flatMap {
           case (sourceFile, name) => {
-            val msg = compile(sourceFile.getPath.replace(assetsDir.getPath + "/", ""), IO.read(sourceFile)).left.map {
+            val msg = compile(sourceFile.getPath.replace(assetsDir.getPath + File.separator , "").replace(File.separator,"/"), IO.read(sourceFile)).left.map {
               case (msg, line, column) => throw AssetCompilationException(Some(sourceFile),
                 msg,
                 line,