diff --git a/ChangeLog b/ChangeLog
index f73c55e5d4..40e294b7d4 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,7 @@
+2014-10-24  Wilco Dijkstra  <wdijkstr@arm.com>
+
+	* string/strncat.c (strncat): Improve performance by using strlen.
+
 2014-10-24  Wilco Dijkstra  <wdijkstr@arm.com>
 
 	* string/strcat.c (strcat): Improve performance by using strlen/strcpy.
diff --git a/string/strncat.c b/string/strncat.c
index 7ac44561bd..6d29114d38 100644
--- a/string/strncat.c
+++ b/string/strncat.c
@@ -33,13 +33,11 @@ STRNCAT (char *s1, const char *s2, size_t n)
   char *s = s1;
 
   /* Find the end of S1.  */
-  do
-    c = *s1++;
-  while (c != '\0');
+  s1 += strlen (s1);
 
   /* Make S1 point before next character, so we can increment
      it while memory is read (wins on pipelined cpus).  */
-  s1 -= 2;
+  s1 -= 1;
 
   if (n >= 4)
     {