diff --git a/contrib/pgbench/pgbench.c b/contrib/pgbench/pgbench.c
index 5a7dc32f9a..1f2e0bf416 100644
--- a/contrib/pgbench/pgbench.c
+++ b/contrib/pgbench/pgbench.c
@@ -1,5 +1,5 @@
 /*
- * $PostgreSQL: pgsql/contrib/pgbench/pgbench.c,v 1.61 2007/01/22 02:17:30 tgl Exp $
+ * $PostgreSQL: pgsql/contrib/pgbench/pgbench.c,v 1.62 2007/03/13 09:06:35 mha Exp $
  *
  * pgbench: a simple benchmark program for PostgreSQL
  * written by Tatsuo Ishii
@@ -1184,6 +1184,11 @@ main(int argc, char **argv)
 
 	char		val[64];
 
+#ifdef WIN32
+	/* stderr is buffered on Win32. */
+	setvbuf(stderr, NULL, _IONBF, 0);
+#endif
+
 	if ((env = getenv("PGHOST")) != NULL && *env != '\0')
 		pghost = env;
 	if ((env = getenv("PGPORT")) != NULL && *env != '\0')