diff --git a/user/src/com/google/gwt/uibinder/rebind/model/ImplicitCssResource.java b/user/src/com/google/gwt/uibinder/rebind/model/ImplicitCssResource.java
index 588921e..747e6b6 100644
--- a/user/src/com/google/gwt/uibinder/rebind/model/ImplicitCssResource.java
+++ b/user/src/com/google/gwt/uibinder/rebind/model/ImplicitCssResource.java
@@ -180,6 +180,7 @@
       try {
         File f = File.createTempFile(String.format("uiBinder_%s_%s",
             packageName, className), ".css");
+        f.deleteOnExit();
 
         BufferedWriter out = new BufferedWriter(new FileWriter(f));
         out.write(body);