diff --git a/nimble/host/test/src/ble_sm_test.c b/nimble/host/test/src/ble_sm_test.c
index 7a2994be7..dcdbaf01e 100644
--- a/nimble/host/test/src/ble_sm_test.c
+++ b/nimble/host/test/src/ble_sm_test.c
@@ -428,6 +428,36 @@ TEST_CASE_SELF(ble_sm_test_case_peer_sec_req_inval)
     ble_hs_test_util_assert_mbufs_freed(NULL);
 }
 
+TEST_CASE_SELF(ble_sm_test_case_peer_sec_req_reject)
+{
+    struct ble_sm_sec_req sec_req;
+    int rc;
+
+    struct ble_sm_pair_cmd pair_rsp = {0x04, 0, 0x0D, 10, 0x02, 0x02};
+
+    ble_sm_test_util_init();
+
+    ble_sm_dbg_set_next_pair_rand(((uint8_t[16]) {0}));
+
+    ble_hs_test_util_create_conn(2, ((uint8_t[6]) {1,2,3,5,6,7}),
+                                 ble_sm_test_util_conn_cb,
+                                 NULL);
+
+    /*** Pairing already in progress; reject security request after pairing
+     * response was received. */
+
+    ble_hs_atomic_conn_set_flags(2, BLE_HS_CONN_F_MASTER, 1);
+    rc = ble_sm_pair_initiate(2);
+    TEST_ASSERT_FATAL(rc == 0);
+    ble_hs_test_util_prev_tx_queue_clear();
+
+    ble_sm_test_util_rx_pair_rsp(2, &pair_rsp, 0);
+    ble_sm_test_util_rx_sec_req(2, &sec_req, BLE_HS_EALREADY);
+    TEST_ASSERT(ble_hs_test_util_prev_tx_queue_sz() != 0);
+
+    ble_hs_test_util_assert_mbufs_freed(NULL);
+}
+
 /*****************************************************************************
  * $us                                                                       *
  *****************************************************************************/
@@ -509,5 +539,6 @@ TEST_SUITE(ble_sm_gen_test_suite)
     ble_sm_test_case_peer_bonding_bad();
     ble_sm_test_case_conn_broken();
     ble_sm_test_case_peer_sec_req_inval();
+    ble_sm_test_case_peer_sec_req_reject();
 }
 #endif
diff --git a/nimble/host/test/src/ble_sm_test_util.c b/nimble/host/test/src/ble_sm_test_util.c
index e3becdf86..74d40e8b5 100644
--- a/nimble/host/test/src/ble_sm_test_util.c
+++ b/nimble/host/test/src/ble_sm_test_util.c
@@ -717,7 +717,7 @@ ble_sm_test_util_rx_pair_req(uint16_t conn_handle,
                                  req, rx_status);
 }
 
-static void
+void
 ble_sm_test_util_rx_pair_rsp(uint16_t conn_handle, struct ble_sm_pair_cmd *rsp,
                              int rx_status)
 {
diff --git a/nimble/host/test/src/ble_sm_test_util.h b/nimble/host/test/src/ble_sm_test_util.h
index d9aa3805c..3ddc86c1f 100644
--- a/nimble/host/test/src/ble_sm_test_util.h
+++ b/nimble/host/test/src/ble_sm_test_util.h
@@ -96,6 +96,9 @@ void ble_sm_test_util_io_check_post(
 void ble_sm_test_util_rx_sec_req(uint16_t conn_handle,
                                  struct ble_sm_sec_req *cmd,
                                  int exp_status);
+void ble_sm_test_util_rx_pair_rsp(uint16_t conn_handle,
+                                  struct ble_sm_pair_cmd *rsp,
+                                  int rx_status);
 void ble_sm_test_util_verify_tx_pair_fail(struct ble_sm_pair_fail *exp_cmd);
 void ble_sm_test_util_us_lgcy_good(struct ble_sm_test_params *params);
 void ble_sm_test_util_peer_fail_inval(int we_are_master,