diff --git a/nimble/controller/src/ble_ll_conn.c b/nimble/controller/src/ble_ll_conn.c
index a15773257..cb80250f9 100644
--- a/nimble/controller/src/ble_ll_conn.c
+++ b/nimble/controller/src/ble_ll_conn.c
@@ -3808,7 +3808,7 @@ ble_ll_conn_rx_isr_end(uint8_t *rxbuf, struct ble_mbuf_hdr *rxhdr)
      * available, we don't need to allocate buffer for this packet so LL will
      * nak it.
      */
-    if (ble_ll_conn_cth_flow_is_enabled() &&
+    if (alloc_rxpdu && ble_ll_conn_cth_flow_is_enabled() &&
         BLE_LL_LLID_IS_DATA(hdr_byte) && (rx_pyld_len > 0)) {
         if (ble_ll_conn_cth_flow_alloc_credit(connsm)) {
             rxhdr->rxinfo.flags |= BLE_MBUF_HDR_F_CONN_CREDIT;