diff --git a/libstdc++-v3/bits/char_traits.h b/libstdc++-v3/bits/char_traits.h
index ae46dd29add..50b51b8bd5a 100644
--- a/libstdc++-v3/bits/char_traits.h
+++ b/libstdc++-v3/bits/char_traits.h
@@ -244,7 +244,7 @@ namespace std {
       static int 
       compare(const char_type* __s1, const char_type* __s2, size_t __n)
       { 
-	for (int_type __i = 0; __i < __n; ++__i)
+	for (size_t __i = 0; __i < __n; ++__i)
 	  if (!eq(__s1[__i], __s2[__i]))
 	    return lt(__s1[__i], __s2[__i]) ? -1 : 1;
 	return 0;