diff --git a/build.gradle b/build.gradle
index 09f9968d..68d0e4d6 100644
--- a/build.gradle
+++ b/build.gradle
@@ -44,6 +44,7 @@ subprojects {
     }
 }
 import java.util.jar.*
+import java.nio.file.*
 void stripJar(File file) {
     if (file.getName().endsWith('.tar'))
         return
@@ -59,7 +60,9 @@ void stripJar(File file) {
             out << jf.getInputStream(it)
         }
         out.finish()
+        jf.close()
     }
-    newFile.renameTo file
+    Files.copy(newFile.toPath(), file.toPath(), StandardCopyOption.REPLACE_EXISTING)
+    newFile.delete()
 }
 
diff --git a/gui/build.gradle b/gui/build.gradle
index ef663579..0f576a96 100644
--- a/gui/build.gradle
+++ b/gui/build.gradle
@@ -160,21 +160,24 @@ task griffonManifest {
         def controllerFile = new File(manifest, "griffon.core.artifact.GriffonController")
         controllerFile.withPrintWriter("US-ASCII", {writer ->
             controllers.each {controller ->
-                writer.println(controller)
+                writer.print(controller)
+                writer.print('\n')
             }
         })
 
         def modelsFile = new File(manifest, "griffon.core.artifact.GriffonModel")
         modelsFile.withPrintWriter("US-ASCII", {writer ->
             models.each {model ->
-                writer.println(model)
+                writer.print(model)
+                writer.print('\n')
             }
         })
 
         def viewsFile = new File(manifest, "griffon.core.artifact.GriffonView")
         viewsFile.withPrintWriter("US-ASCII", {writer ->
             views.each {view ->
-                writer.println(view)
+                writer.print(view)
+                writer.print('\n')
             }
         })
     }