diff --git a/util/io/FileUtilities.scala b/util/io/FileUtilities.scala
index 83563740f..14a91c90d 100644
--- a/util/io/FileUtilities.scala
+++ b/util/io/FileUtilities.scala
@@ -247,7 +247,7 @@ object FileUtilities
 				()
 			else if(sourceFile.exists)
 			{
-				val nextEntry = createEntry(name)
+				val nextEntry = createEntry(normalizeName(name))
 				nextEntry.setTime(sourceFile.lastModified)
 				output.putNextEntry(nextEntry)
 				transferAndClose(new FileInputStream(sourceFile), output)
@@ -258,6 +258,11 @@ object FileUtilities
 		sources.foreach(tupled(add))
 		output.closeEntry()
 	}
+	private def normalizeName(name: String) =
+	{
+		val sep = File.separatorChar
+		if(sep == '/') name else name.replace(sep, '/')
+	}
 
 	private def withZipOutput(file: File, manifest: Option[Manifest])(f: ZipOutputStream => Unit)
 	{