--- core/src/classpath/java/java/io/VMFile.java
+++ core/src/classpath/java/java/io/VMFile.java
@@ -88,7 +88,22 @@
      */
     static boolean renameTo(String targetpath, String destpath) {
         try{
-            //todo improve it
+			targetPath = getNormalizedPath(targetPath);
+			destpath = getNormalizedPath(destpath);
+            /*
+			 * Check if the destination file exists, if it does fail
+			 */
+			if(VMIOUtils.getAPI().fileExists(destpath))
+				return false;
+			/*
+			 * If source and dest have the same parent, simply rename the file
+			 */
+			if(targetpath.substring(0, targetpath.lastIndexOf("/")).compareTo(destpath.substring(0, destpath.lastIndexOf("/"))) == 0) {
+				/* Same parent, let's rename */
+				return new File(targetpath).renameTo(destpath);
+			}
+			/* Different parents, determine if they are on the same file system */
+			/* NOTE: Could not figure out way to determine if on different filesystem */
             FileInputStream fis = new FileInputStream(targetpath);
             FileOutputStream fos = new FileOutputStream(destpath);
             byte[] buf = new byte[64*1024];