diff --git a/ChangeLog b/ChangeLog
index 1258a0260d..eb1bdae39a 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Thu Aug 15 18:39:31 2013  NAKAMURA Usaku  <usa@ruby-lang.org>
+
+	* win32/win32.c (clock_gettime): improve precision when freq is less
+	  than and nearly equals 10**9.
+
 Thu Aug 15 17:43:15 2013  Koichi Sasada  <ko1@atdot.net>
 
 	* gc.c (gc_lazy_sweep): remove heap_increment() here because heap_inc
diff --git a/win32/win32.c b/win32/win32.c
index 95e201092b..c64b7b99e3 100644
--- a/win32/win32.c
+++ b/win32/win32.c
@@ -4339,7 +4339,7 @@ clock_gettime(clockid_t clock_id, struct timespec *sp)
 	    }
 	    sp->tv_sec = count.QuadPart / freq.QuadPart;
 	    if (freq.QuadPart < 1000000000)
-		sp->tv_nsec = (count.QuadPart % freq.QuadPart) * (1000000000 / freq.QuadPart);
+		sp->tv_nsec = (count.QuadPart % freq.QuadPart) * 1000000000 / freq.QuadPart;
 	    else
 		sp->tv_nsec = (long)((count.QuadPart % freq.QuadPart) * (1000000000.0 / freq.QuadPart));
 	    return 0;