-	return s;
-    }
-  while (c != '\0');
-
- zero_fill:
-  do
-    *++s1 = '\0';
-  while (--n > 0);
-
-  return s;
+  size_t size = __strnlen (s2, n);
+  if (size != n)
+    memset (s1 + size, '\0', n - size);
+  return memcpy (s1, s2, size);
 }
 libc_hidden_builtin_def (strncpy)
diff --git a/sysdeps/gnu/bits/utmp.h b/sysdeps/gnu/bits/utmp.h
index aed2750..434a533 100644