diff --git a/nimble/controller/include/controller/ble_ll.h b/nimble/controller/include/controller/ble_ll.h
index cd9ae92ed..4220d439c 100644
--- a/nimble/controller/include/controller/ble_ll.h
+++ b/nimble/controller/include/controller/ble_ll.h
@@ -451,6 +451,7 @@ int ble_ll_rx_end(uint8_t *rxbuf, struct ble_mbuf_hdr *rxhdr);
 
 /* Helper callback to tx mbuf using ble_phy_tx() */
 uint8_t ble_ll_tx_mbuf_pducb(uint8_t *dptr, void *pducb_arg, uint8_t *hdr_byte);
+uint8_t ble_ll_tx_flat_mbuf_pducb(uint8_t *dptr, void *pducb_arg, uint8_t *hdr_byte);
 
 /*--- Controller API ---*/
 void ble_ll_mbuf_init(struct os_mbuf *m, uint8_t pdulen, uint8_t hdr);
diff --git a/nimble/controller/src/ble_ll.c b/nimble/controller/src/ble_ll.c
index 5587c28ce..0cf4d84a7 100644
--- a/nimble/controller/src/ble_ll.c
+++ b/nimble/controller/src/ble_ll.c
@@ -1017,6 +1017,23 @@ ble_ll_tx_mbuf_pducb(uint8_t *dptr, void *pducb_arg, uint8_t *hdr_byte)
     return ble_hdr->txinfo.pyld_len;
 }
 
+uint8_t
+ble_ll_tx_flat_mbuf_pducb(uint8_t *dptr, void *pducb_arg, uint8_t *hdr_byte)
+{
+    struct os_mbuf *txpdu;
+    struct ble_mbuf_hdr *ble_hdr;
+
+    txpdu = pducb_arg;
+    BLE_LL_ASSERT(txpdu);
+    ble_hdr = BLE_MBUF_HDR_PTR(txpdu);
+
+    memcpy(dptr, txpdu->om_data, ble_hdr->txinfo.pyld_len);
+
+    *hdr_byte = ble_hdr->txinfo.hdr_byte;
+
+    return ble_hdr->txinfo.pyld_len;
+}
+
 static void
 ble_ll_event_rx_pkt(struct ble_npl_event *ev)
 {
diff --git a/nimble/controller/src/ble_ll_conn.c b/nimble/controller/src/ble_ll_conn.c
index 699da4328..0d19f05a7 100644
--- a/nimble/controller/src/ble_ll_conn.c
+++ b/nimble/controller/src/ble_ll_conn.c
@@ -2868,7 +2868,7 @@ ble_ll_conn_request_send(uint8_t addr_type, uint8_t *adva, uint16_t txoffset,
     } else {
         ble_phy_set_txend_cb(ble_ll_conn_req_txend_init, NULL);
     }
-    rc = ble_phy_tx(ble_ll_tx_mbuf_pducb, m, end_trans);
+    rc = ble_phy_tx(ble_ll_tx_flat_mbuf_pducb, m, end_trans);
     return rc;
 }
 
@@ -3057,6 +3057,55 @@ ble_ll_init_rx_isr_start(uint8_t pdu_type, struct ble_mbuf_hdr *ble_hdr)
 
     return 0;
 }
+
+/**
+ * Make a connect request PDU
+ *
+ * @param connsm
+ */
+static void
+ble_ll_conn_req_pdu_make(struct ble_ll_conn_sm *connsm, uint8_t chan)
+{
+    uint8_t pdu_type;
+    uint8_t *dptr;
+    struct os_mbuf *m;
+
+    m = ble_ll_scan_get_pdu();
+    BLE_LL_ASSERT(m != NULL);
+
+    /* Construct first PDU header byte */
+    pdu_type = BLE_ADV_PDU_TYPE_CONNECT_REQ;
+
+#if (MYNEWT_VAL(BLE_LL_CFG_FEAT_LE_CSA2) == 1)
+    /* We need CSA2 bit only for legacy connect */
+    if (chan >= BLE_PHY_NUM_DATA_CHANS) {
+        pdu_type |= BLE_ADV_PDU_HDR_CHSEL;
+    }
+#endif
+
+    /* Set BLE transmit header */
+    ble_ll_mbuf_init(m, BLE_CONNECT_REQ_LEN, pdu_type);
+
+    /* Construct the connect request */
+    dptr = m->om_data;
+
+    /* Skip inita and adva advertiser's address as we dont know that yet */
+    dptr += (2 * BLE_DEV_ADDR_LEN);
+
+    /* Access address */
+    put_le32(dptr, connsm->access_addr);
+    dptr[4] = (uint8_t)connsm->crcinit;
+    dptr[5] = (uint8_t)(connsm->crcinit >> 8);
+    dptr[6] = (uint8_t)(connsm->crcinit >> 16);
+    dptr[7] = connsm->tx_win_size;
+    put_le16(dptr + 8, connsm->tx_win_off);
+    put_le16(dptr + 10, connsm->conn_itvl);
+    put_le16(dptr + 12, connsm->slave_latency);
+    put_le16(dptr + 14, connsm->supervision_tmo);
+    memcpy(dptr + 16, &connsm->chanmap, BLE_LL_CONN_CHMAP_LEN);
+    dptr[21] = connsm->hop_inc | (connsm->master_sca << 5);
+}
+
 /**
  * Called when a receive PDU has ended and we are in the initiating state.
  *
diff --git a/nimble/controller/src/ble_ll_conn_hci.c b/nimble/controller/src/ble_ll_conn_hci.c
index 5274d15c5..570cf1a62 100644
--- a/nimble/controller/src/ble_ll_conn_hci.c
+++ b/nimble/controller/src/ble_ll_conn_hci.c
@@ -123,54 +123,6 @@ ble_ll_conn_hci_chk_conn_params(uint16_t itvl_min, uint16_t itvl_max,
     return BLE_ERR_SUCCESS;
 }
 
-/**
- * Make a connect request PDU
- *
- * @param connsm
- */
-void
-ble_ll_conn_req_pdu_make(struct ble_ll_conn_sm *connsm, uint8_t chan)
-{
-    uint8_t pdu_type;
-    uint8_t *dptr;
-    struct os_mbuf *m;
-
-    m = ble_ll_scan_get_pdu();
-    BLE_LL_ASSERT(m != NULL);
-
-    /* Construct first PDU header byte */
-    pdu_type = BLE_ADV_PDU_TYPE_CONNECT_REQ;
-
-#if (MYNEWT_VAL(BLE_LL_CFG_FEAT_LE_CSA2) == 1)
-    /* We need CSA2 bit only for legacy connect */
-    if (chan >= BLE_PHY_NUM_DATA_CHANS) {
-        pdu_type |= BLE_ADV_PDU_HDR_CHSEL;
-    }
-#endif
-
-    /* Set BLE transmit header */
-    ble_ll_mbuf_init(m, BLE_CONNECT_REQ_LEN, pdu_type);
-
-    /* Construct the connect request */
-    dptr = m->om_data;
-
-    /* Skip inita and adva advertiser's address as we dont know that yet */
-    dptr += (2 * BLE_DEV_ADDR_LEN);
-
-    /* Access address */
-    put_le32(dptr, connsm->access_addr);
-    dptr[4] = (uint8_t)connsm->crcinit;
-    dptr[5] = (uint8_t)(connsm->crcinit >> 8);
-    dptr[6] = (uint8_t)(connsm->crcinit >> 16);
-    dptr[7] = connsm->tx_win_size;
-    put_le16(dptr + 8, connsm->tx_win_off);
-    put_le16(dptr + 10, connsm->conn_itvl);
-    put_le16(dptr + 12, connsm->slave_latency);
-    put_le16(dptr + 14, connsm->supervision_tmo);
-    memcpy(dptr + 16, &connsm->chanmap, BLE_LL_CONN_CHMAP_LEN);
-    dptr[21] = connsm->hop_inc | (connsm->master_sca << 5);
-}
-
 /**
  * Send a connection complete event
  *
diff --git a/nimble/controller/src/ble_ll_conn_priv.h b/nimble/controller/src/ble_ll_conn_priv.h
index 581de37e1..5cc509f0b 100644
--- a/nimble/controller/src/ble_ll_conn_priv.h
+++ b/nimble/controller/src/ble_ll_conn_priv.h
@@ -182,7 +182,6 @@ int ble_ll_hci_acl_rx(struct os_mbuf *om, void *arg);
 int ble_ll_conn_hci_le_rd_phy(uint8_t *cmdbuf, uint8_t *rsp, uint8_t *rsplen);
 int ble_ll_conn_hci_le_set_phy(uint8_t *cmdbuf);
 int ble_ll_conn_chk_phy_upd_start(struct ble_ll_conn_sm *connsm);
-void ble_ll_conn_req_pdu_make(struct ble_ll_conn_sm *connsm, uint8_t chan);
 #if MYNEWT_VAL(BLE_LL_CFG_FEAT_LL_EXT_ADV)
 int ble_ll_ext_conn_create(uint8_t *cmdbuf);
 #endif