diff --git a/lib/defines.h b/lib/defines.h
index ab4f9a77..917f9fe5 100644
--- a/lib/defines.h
+++ b/lib/defines.h
@@ -72,7 +72,7 @@ static const char * DBG_LVL_LIST[] = {"NONE", "FAIL", "ERROR", "WARN", "INFO", "
 #define SHM_STREAM_INDEX "MstSTRM%s" //%s stream name
 #define SHM_TRACK_META "MstTRAK%s@%lu" //%s stream name, %lu track ID
 #define SHM_TRACK_INDEX "MstTRID%s@%lu" //%s stream name, %lu track ID
-#define SHM_TRACK_DATA "MstDATA%s@%lu+%lu" //%s stream name, %lu track ID, %lu page #
+#define SHM_TRACK_DATA "MstDATA%s@%lu_%lu" //%s stream name, %lu track ID, %lu page #
 #define SHM_STATISTICS "MstSTAT"
 #define SHM_USERS "MstUSER%s" //%s stream name
 #define SEM_LIVE "MstLIVE%s" //%s stream name