diff --git a/test/litest-int.h b/test/litest-int.h
index ab611a56..ffa30a74 100644
--- a/test/litest-int.h
+++ b/test/litest-int.h
@@ -97,8 +97,8 @@ struct litest_device_interface {
 	struct input_event *touch_move_events;
 	struct input_event *touch_up_events;
 
-	int min[2];
-	int max[2];
+	int min[2]; /* x/y axis minimum */
+	int max[2]; /* x/y axis maximum */
 };
 
 void litest_set_current_device(struct litest_device *device);