diff --git a/ChangeLog b/ChangeLog
index 8c100e32..18afbdae 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -165,6 +165,8 @@
 	- Don't free extent inodes in attrib.c! (Szakacsits Szabolcs)
 	- Return the attribute list attribute when enumerating attributes, too.
 	  Thanks to Szakacsits Szabolcs for pointing this problem out.
+	- New API function provided by unistr.[hc] and use it in mkntfs:
+		ntfs_ucsnlen().
 
 12/03/2002 - 1.6.0 - More mkntfs options and cleanups.
 	Fix typo in usage information of mkntfs. Thanks to Richard Russon for
diff --git a/include/unistr.h b/include/unistr.h
index 73c99f2c..7b1c45a6 100644
--- a/include/unistr.h
+++ b/include/unistr.h
@@ -42,6 +42,8 @@ extern int ntfs_ucsncmp(const uchar_t *s1, const uchar_t *s2, size_t n);
 extern int ntfs_ucsncasecmp(const uchar_t *s1, const uchar_t *s2, size_t n,
 		const uchar_t *upcase, const u32 upcase_size);
 
+extern u32 ntfs_ucsnlen(const uchar_t *s, u32 maxlen);
+
 extern void ntfs_name_upcase(uchar_t *name, u32 name_len,
 		const uchar_t *upcase, const u32 upcase_len);
 
diff --git a/libntfs/unistr.c b/libntfs/unistr.c
index 9376cc34..b7f0d014 100644
--- a/libntfs/unistr.c
+++ b/libntfs/unistr.c
@@ -227,6 +227,29 @@ int ntfs_ucsncasecmp(const uchar_t *s1, const uchar_t *s2, size_t n,
 	return 0;
 }
 
+/**
+ * ntfs_ucsnlen - determine the length of a little endian Unicode string
+ * @s:		pointer to Unicode string
+ * @maxlen:	maximum length of string @s
+ *
+ * Return the number of Unicode characters in the little endian Unicode
+ * string @s up to a maximum of maxlen Unicode characters, not including
+ * the terminating (uchar_t)'\0'. If there is no (uchar_t)'\0' between @s
+ * and @s + @maxlen, @maxlen is returned.
+ *
+ * This function never looks beyond @s + @maxlen.
+ */
+u32 ntfs_ucsnlen(const uchar_t *s, u32 maxlen)
+{
+	u32 i;
+
+	for (i = 0; i < maxlen; i++) {
+		if (!le16_to_cpu(s[i]))
+			break;
+	}
+	return i;
+}
+
 /**
  * ntfs_name_upcase
  */