diff --git a/lib/dbi/session.c b/lib/dbi/session.c
index 9b58c5b1a..0291f6e79 100644
--- a/lib/dbi/session.c
+++ b/lib/dbi/session.c
@@ -43,7 +43,6 @@ int ogs_dbi_session_data(char *supi, ogs_s_nssai_t *s_nssai, char *dnn,
     ogs_session_data_t zero_data;
 
     ogs_assert(supi);
-    ogs_assert(s_nssai);
     ogs_assert(dnn);
     ogs_assert(session_data);
 
@@ -122,9 +121,10 @@ int ogs_dbi_session_data(char *supi, ogs_s_nssai_t *s_nssai, char *dnn,
                     continue;
                 }
 
-                if (s_nssai->sst != sst) continue;
+                if (s_nssai && s_nssai->sst != sst) continue;
 
-                if (s_nssai->sd.v != OGS_S_NSSAI_NO_SD_VALUE &&
+                if (s_nssai &&
+                    s_nssai->sd.v != OGS_S_NSSAI_NO_SD_VALUE &&
                     sd.v != OGS_S_NSSAI_NO_SD_VALUE) {
                     if (s_nssai->sd.v != sd.v) continue;
                 }
@@ -150,7 +150,10 @@ int ogs_dbi_session_data(char *supi, ogs_s_nssai_t *s_nssai, char *dnn,
 done:
     if (found == false) {
         ogs_error("Cannot find SUPI[%s] S_NSSAI[SST:%d SD:0x%x] DNN[%s] in DB",
-                supi_id, s_nssai->sst, s_nssai->sd.v, dnn);
+                supi_id,
+                s_nssai ? s_nssai->sst : 0,
+                s_nssai ? s_nssai->sd.v : 0,
+                dnn);
 
         rv = OGS_ERROR;
         goto out;
diff --git a/src/hss/hss-s6a-path.c b/src/hss/hss-s6a-path.c
index 46a8b8ce3..e3ce47c3e 100644
--- a/src/hss/hss-s6a-path.c
+++ b/src/hss/hss-s6a-path.c
@@ -277,7 +277,6 @@ static int hss_ogs_diam_s6a_ulr_cb( struct msg **msg, struct avp *avp,
     union avp_value val;
 
     char imsi_bcd[OGS_MAX_IMSI_BCD_LEN+1];
-    ogs_s_nssai_t s_nssai;
 
     int rv;
     uint32_t result_code = 0;
@@ -463,13 +462,10 @@ static int hss_ogs_diam_s6a_ulr_cb( struct msg **msg, struct avp *avp,
         ret = fd_msg_avp_add(avp, MSG_BRW_LAST_CHILD, avp_rau_tau_timer);
         ogs_assert(ret == 0);
 
-        /* For EPC, we'll use SST:1 */
-        s_nssai.sst = 1;
-        s_nssai.sd.v = OGS_S_NSSAI_NO_SD_VALUE;
+        /* For EPC, we'll use first Slice in Subscription */
+        if (subscription_data.num_of_slice)
+            slice_data = &subscription_data.slice[0];
 
-        slice_data = ogs_slice_find_by_s_nssai(
-                subscription_data.slice, subscription_data.num_of_slice,
-                &s_nssai);
         if (!slice_data) {
             ogs_error("[%s] Cannot find S-NSSAI", imsi_bcd);
             result_code = OGS_DIAM_S6A_ERROR_UNKNOWN_EPS_SUBSCRIPTION;
diff --git a/src/hss/hss-swx-path.c b/src/hss/hss-swx-path.c
index da4ac1f1d..d54dd6f76 100644
--- a/src/hss/hss-swx-path.c
+++ b/src/hss/hss-swx-path.c
@@ -388,7 +388,6 @@ static int hss_ogs_diam_swx_sar_cb( struct msg **msg, struct avp *avp,
     union avp_value val;
 
     char *user_name = NULL;
-    ogs_s_nssai_t s_nssai;
 
     char imsi_bcd[OGS_MAX_IMSI_BCD_LEN+1];
 
@@ -557,13 +556,10 @@ static int hss_ogs_diam_swx_sar_cb( struct msg **msg, struct avp *avp,
         ret = fd_msg_avp_add(avp, MSG_BRW_LAST_CHILD, avp_ambr);
         ogs_assert(ret == 0);
 
-        /* For EPC, we'll use SST:1 */
-        s_nssai.sst = 1;
-        s_nssai.sd.v = OGS_S_NSSAI_NO_SD_VALUE;
+        /* For EPC, we'll use first Slice in Subscription */
+        if (subscription_data.num_of_slice)
+            slice_data = &subscription_data.slice[0];
 
-        slice_data = ogs_slice_find_by_s_nssai(
-                subscription_data.slice, subscription_data.num_of_slice,
-                &s_nssai);
         if (!slice_data) {
             ogs_error("[%s] Cannot find S-NSSAI", imsi_bcd);
             result_code = OGS_DIAM_S6A_ERROR_UNKNOWN_EPS_SUBSCRIPTION;
diff --git a/src/pcrf/pcrf-context.c b/src/pcrf/pcrf-context.c
index 534e5447b..d954f7200 100644
--- a/src/pcrf/pcrf-context.c
+++ b/src/pcrf/pcrf-context.c
@@ -271,7 +271,6 @@ int pcrf_db_qos_data(
 {
     int rv, i;
     char *supi = NULL;
-    ogs_s_nssai_t s_nssai;
 
     ogs_assert(imsi_bcd);
     ogs_assert(apn);
@@ -281,11 +280,8 @@ int pcrf_db_qos_data(
     supi = ogs_msprintf("%s-%s", OGS_ID_SUPI_TYPE_IMSI, imsi_bcd);
     ogs_assert(supi);
 
-    /* For EPC, we'll use SST:1 */
-    s_nssai.sst = 1;
-    s_nssai.sd.v = OGS_S_NSSAI_NO_SD_VALUE;
-
-    rv = ogs_dbi_session_data(supi, &s_nssai, apn, session_data);
+    /* For EPC, we'll use [S_NSSAI = NULL] */
+    rv = ogs_dbi_session_data(supi, NULL, apn, session_data);
 
     /* For EPC, we need to inialize Flow-Status in Pcc-Rule */
     for (i = 0; i < session_data->num_of_pcc_rule; i++) {