diff --git a/php-fastcommon/test.php b/php-fastcommon/test.php
index 35fbd62..8a98992 100644
--- a/php-fastcommon/test.php
+++ b/php-fastcommon/test.php
@@ -18,6 +18,7 @@ while (($next_ip=fastcommon_get_next_local_ip($next_ip)))
 
 fastcommon_id_generator_init("/tmp/sn.txt");
 
+var_dump(fastcommon_id_generator_next());
 for ($i=0; $i<10; $i++) {
 	echo fastcommon_id_generator_next() . "\n";
 }
diff --git a/src/id_generator.c b/src/id_generator.c
index a5fd9ea..d3f3865 100644
--- a/src/id_generator.c
+++ b/src/id_generator.c
@@ -173,7 +173,7 @@ int id_generator_next(struct idg_context *context, int64_t *id)
 			break;
 		}
 
-		len = sprintf(buff, "%019"PRId64, sn);
+		len = sprintf(buff, "%-20"PRId64, sn);
 		if ((bytes=write(context->fd, buff, len)) != len)
 		{
 			result = errno != 0 ? errno : EACCES;
diff --git a/src/tests/test_id_generator.c b/src/tests/test_id_generator.c
index 2c4f130..f1c2e61 100644
--- a/src/tests/test_id_generator.c
+++ b/src/tests/test_id_generator.c
@@ -21,7 +21,7 @@ int main(int argc, char *argv[])
 	int i;
 	int64_t id;
 	const int machine_id = 0;
-	const int mid_bits = 8;
+	const int mid_bits = 12;
 	
 	log_init();
 	g_log_context.log_level = LOG_DEBUG;
@@ -35,15 +35,15 @@ int main(int argc, char *argv[])
 	}
 
 	//id_generator_next(&context, &id);
-	//printf("id: %"PRId64", %016llX\n", id, id);
-	for (i=0; i<10000; i++)
+	//printf("id: %"PRId64", %016lX\n", id, id);
+	for (i=0; i<100; i++)
 	{
 		result = id_generator_next(&context, &id);
 		if (result != 0)
 		{
 			break;
 		}
-		printf("%"PRId64", %016llX\n", id, id);
+		printf("%"PRId64", %016lX\n", id, id);
 	}
 
 	id_generator_destroy(&context);