diff --git a/src/timeline.h b/src/timeline.h
index 38727def50b5a81c073ab23375f0c548ca096b66..09161b3ec68e9f7c19bf812103384257473f5719 100644
--- a/src/timeline.h
+++ b/src/timeline.h
@@ -40,6 +40,9 @@ typedef char timebin_t;
 /*! Fictious time-bin to hold inhibited particles */
 #define time_bin_inhibited (num_time_bins + 2)
 
+/*! Fictious time-bin to hold particles not yet created */
+#define time_bin_not_created (num_time_bins + 3)
+
 /*! Fictitious time-bin for particles not awaken */
 #define time_bin_not_awake (0)