diff --git a/src/main/java/erjang/driver/efile/EFile.java b/src/main/java/erjang/driver/efile/EFile.java
index 40f66c12..315fa4bf 100644
--- a/src/main/java/erjang/driver/efile/EFile.java
+++ b/src/main/java/erjang/driver/efile/EFile.java
@@ -361,6 +361,9 @@ public static class Info {
 	public static final byte FILE_RESP_LDATA = 6;
 	public static final byte FILE_RESP_N2DATA = 7;
 	public static final byte FILE_RESP_EOF = 8;
+	public static final byte FILE_RESP_FNAME = 9;
+	public static final byte FILE_RESP_ALL_DATA = 10;
+	private static final byte[] FILE_RESP_ALL_DATA_HEADER = new byte[]{ FILE_RESP_ALL_DATA };
 
 	/* Options */
 
@@ -877,7 +880,7 @@ public void ready() throws Pausable {
 					}
 					
 					binp.flip();
-					driver_output_binary(FILE_RESP_OK_HEADER, binp);
+					driver_output_binary(isUnicodeDriverInterface() ? FILE_RESP_ALL_DATA_HEADER : FILE_RESP_OK_HEADER, binp);
 				}
 
 			};
@@ -1389,10 +1392,22 @@ public void ready() throws Pausable {
 					if (!result_ok) {
 						reply_posix_error(posix_errno);
 					} else {
-						ByteBuffer reply = ByteBuffer.allocate(1+pwd.length());
-						reply.put(FILE_RESP_OK);
-						IO.putstr(reply, pwd, false);
-						driver_output2(reply, null);
+						ByteBuffer reply = null;
+						ByteBuffer data = null;
+						if (isUnicodeDriverInterface()) {
+							// prim_file interface from R14 on
+							reply = ByteBuffer.allocate(1);
+							data = ByteBuffer.allocate(pwd.length());
+							reply.put(FILE_RESP_FNAME);
+							IO.putstr(data, pwd, false);
+						}
+						else {
+							// prim_file interface up to R13B
+							reply = ByteBuffer.allocate(1+pwd.length());
+							reply.put(FILE_RESP_OK);
+							IO.putstr(reply, pwd, false);
+						}
+						driver_output2(reply, data);
 					}
 				}
 
@@ -1902,19 +1917,55 @@ public String toString() {
 
 	void reply_list_directory(String[] files) throws Pausable {
 		for (int i = 0; i < files.length; i++) {
-			ByteBuffer resbuf = ByteBuffer.allocate(files[i].length()+1);
-			resbuf.put(FILE_RESP_OK);
-			resbuf.limit(resbuf.capacity());
-			resbuf.position(1);
-			
-			IO.putstr(resbuf, files[i], false);
-			
-			driver_output2(resbuf, null);
+			if (isUnicodeDriverInterface()) {
+				// prim_file interface from R14 on
+				ByteBuffer reply = ByteBuffer.allocate(1);
+				reply.put(FILE_RESP_FNAME);
+				
+				ByteBuffer data = ByteBuffer.allocate(files[i].length());
+				data.limit(data.capacity());
+				data.position(0);
+				IO.putstr(data, files[i], false);
+				
+				driver_output2(reply, data);
+			}
+			else {
+				// prim_file interface up to R13B
+				ByteBuffer resbuf = ByteBuffer.allocate(files[i].length()+1);
+				resbuf.put(FILE_RESP_OK);
+				resbuf.limit(resbuf.capacity());
+				resbuf.position(1);
+				
+				IO.putstr(resbuf, files[i], false);
+				
+				driver_output2(resbuf, null);
+			}
 		}
 		
 		ByteBuffer resbuf = ByteBuffer.allocate(1);
-		resbuf.put(FILE_RESP_OK);
+		resbuf.put(isUnicodeDriverInterface() ? FILE_RESP_FNAME : FILE_RESP_OK);
 		driver_output2(resbuf, null);
 	}
 	
+	/**
+	 * the new unicode driver interface is used since OTP version R14B01.
+	 * 
+	 * @see http://www.erlang.org/doc/apps/stdlib/unicode_usage.html#id60205
+	 */
+	static boolean unicodeDriverInterface = ("R14B".compareTo(erjang.Main.OTP_VERSION) <= 0);
+	
+	/**
+	 * Determine whether to use the new unicode driver interface
+	 * from R14B01.
+	 * 
+	 * @return <code>true</code>, if the new driver interface
+	 * from R14B01 is to be used, <code>false</code> for the older 
+	 * driver interface up to R13
+	 * 
+	 * @see http://www.erlang.org/doc/apps/stdlib/unicode_usage.html#id60205
+	 */
+	private static boolean isUnicodeDriverInterface() {
+		return unicodeDriverInterface;
+	}
+	
 }