diff --git a/src/bts.cpp b/src/bts.cpp
index f77c5a2..df08cc6 100644
--- a/src/bts.cpp
+++ b/src/bts.cpp
@@ -1389,7 +1389,7 @@
 
 struct GprsMs *bts_ms_by_imsi(struct gprs_rlcmac_bts *bts, const char *imsi)
 {
-	return bts_ms_store(bts)->get_ms(0, 0, imsi);
+	return bts_ms_store(bts)->get_ms(GSM_RESERVED_TMSI, GSM_RESERVED_TMSI, imsi);
 }
 
 const struct llist_head* bts_ms_list(struct gprs_rlcmac_bts *bts)
diff --git a/src/pcu_vty_functions.cpp b/src/pcu_vty_functions.cpp
index 1745eea..28ecebf 100644
--- a/src/pcu_vty_functions.cpp
+++ b/src/pcu_vty_functions.cpp
@@ -236,7 +236,7 @@
 int pcu_vty_show_ms_by_imsi(struct vty *vty, struct gprs_rlcmac_bts *bts,
 	const char *imsi)
 {
-	GprsMs *ms = bts_ms_store(bts)->get_ms(0, 0, imsi);
+	GprsMs *ms = bts_ms_store(bts)->get_ms(GSM_RESERVED_TMSI, GSM_RESERVED_TMSI, imsi);
 	if (!ms) {
 		vty_out(vty, "Unknown IMSI '%s'.%s", imsi, VTY_NEWLINE);
 		return CMD_WARNING;
diff --git a/src/tbf.cpp b/src/tbf.cpp
index d15cd3d..cb5d9f3 100644
--- a/src/tbf.cpp
+++ b/src/tbf.cpp
@@ -225,7 +225,7 @@
 	if (!ms_check_tlli(ms(), tlli)) {
 		GprsMs *old_ms;
 
-		old_ms = bts_ms_store(bts)->get_ms(tlli, 0, NULL);
+		old_ms = bts_ms_store(bts)->get_ms(tlli, GSM_RESERVED_TMSI, NULL);
 		if (old_ms)
 			ms_merge_and_clear_ms(ms(), old_ms);
 	}
diff --git a/src/tbf_dl.cpp b/src/tbf_dl.cpp
index 9c99cf6..67ac573 100644
--- a/src/tbf_dl.cpp
+++ b/src/tbf_dl.cpp
@@ -295,7 +295,7 @@
 	/* If we got MS by TLLI above let's see if we already have another MS
 	 * object identified by IMSI and merge them */
 	if (ms && !ms_imsi_is_valid(ms) && imsi) {
-		ms_old = bts_ms_store(bts)->get_ms(0, 0, imsi);
+		ms_old = bts_ms_store(bts)->get_ms(GSM_RESERVED_TMSI, GSM_RESERVED_TMSI, imsi);
 		if (ms_old && ms_old != ms) {
 			/* The TLLI has changed (RAU), so there are two MS
 			 * objects for the same MS */