diff --git a/src/amf/nudm-handler.c b/src/amf/nudm-handler.c
index 9bf5d85483..beb697f53c 100644
--- a/src/amf/nudm-handler.c
+++ b/src/amf/nudm-handler.c
@@ -134,25 +134,38 @@ int amf_nudm_sdm_handle_provisioned(
             }
         }
 
+    /* 
+     * TS23.501
+     *
+     * 5.15.4 UE NSSAI configuration and NSSAI storage aspects
+     * 5.15.4.1 General
+     * 5.15.4.1.1 UE Network Slice configuration
+     *
+     * S-NSSAIs that the UE provides in the Requested NSSAI which are neither
+     * in the Allowed NSSAI nor provided as a rejected S-NSSAI, shall, by the
+     * UE, not be regarded as rejected, i.e. the UE may request to register
+     * these S-NSSAIs again next time the UE sends a Requested NSSAI
+     *
+     * 5.15.5 Detailed Operation Overview
+     *
+     * 5.15.5.2 Selection of a Serving AMF supporting the Network Slices
+     * 5.15.5.2.1 Registration to a set of Network Slices
+     *
+     * AMF checks whether it can serve all the S-NSSAI(s) from
+     * the Requested NSSAI present in the Subscribed S-NSSAIs
+     * (potentially using configuration for mapping S-NSSAI values
+     * between HPLMN and Serving PLMN), or all the S-NSSAI(s) marked
+     * as default in the Subscribed S-NSSAIs in the case that
+     * no Requested NSSAI was provided or none of the S-NSSAIs
+     * in the Requested NSSAI are permitted,
+     * i.e. do not match any of the Subscribed S-NSSAIs or not available
+     * at the current UE's Tracking Area (see clause 5.15.3).
+     */
+
         amf_ue->allowed_nssai.num_of_s_nssai = 0;
         amf_ue->rejected_nssai.num_of_s_nssai = 0;
 
-        if (!amf_ue->requested_nssai.num_of_s_nssai) {
-
-            for (i = 0; i < amf_ue->num_of_slice; i++) {
-                ogs_slice_data_t *slice = &amf_ue->slice[i];
-                ogs_nas_s_nssai_ie_t *allowed =
-                    &amf_ue->allowed_nssai.s_nssai[i];
-
-                allowed->sst = slice->s_nssai.sst;
-                allowed->sd.v = slice->s_nssai.sd.v;
-                allowed->mapped_hplmn_sst = 0;
-                allowed->mapped_hplmn_sd.v = OGS_S_NSSAI_NO_SD_VALUE;
-            }
-            amf_ue->allowed_nssai.num_of_s_nssai = amf_ue->num_of_slice;
-
-        } else {
-
+        if (amf_ue->requested_nssai.num_of_s_nssai) {
             for (i = 0; i < amf_ue->requested_nssai.num_of_s_nssai; i++) {
                 ogs_slice_data_t *slice = NULL;
                 ogs_nas_s_nssai_ie_t *requested =
@@ -191,6 +204,23 @@ int amf_nudm_sdm_handle_provisioned(
             }
         }
 
+        if (!amf_ue->allowed_nssai.num_of_s_nssai) {
+            for (i = 0; i < amf_ue->num_of_slice; i++) {
+                ogs_slice_data_t *slice = &amf_ue->slice[i];
+                ogs_nas_s_nssai_ie_t *allowed =
+                    &amf_ue->allowed_nssai.s_nssai[i];
+
+                if (slice->default_indicator == true) {
+                    allowed->sst = slice->s_nssai.sst;
+                    allowed->sd.v = slice->s_nssai.sd.v;
+                    allowed->mapped_hplmn_sst = 0;
+                    allowed->mapped_hplmn_sd.v = OGS_S_NSSAI_NO_SD_VALUE;
+
+                    amf_ue->allowed_nssai.num_of_s_nssai++;
+                }
+            }
+        }
+
         if (amf_ue->allowed_nssai.num_of_s_nssai) {
             amf_ue->allowed_nssai_present = true;
         } else {
diff --git a/tests/common/context.c b/tests/common/context.c
index 540e14cb6e..bcd5e92475 100644
--- a/tests/common/context.c
+++ b/tests/common/context.c
@@ -1919,6 +1919,7 @@ bson_t *test_db_new_slice(test_ue_t *test_ue)
               "{",
                 "sst", BCON_INT32(1),
                 "sd", BCON_UTF8("009000"),
+                "default_indicator", BCON_BOOL(true),
                 "session", "[",
                   "{",
                     "name", BCON_UTF8("internet"),