diff --git a/lib/iscsi/conn.c b/lib/iscsi/conn.c
index 0f51d1f2a5..1cf5334499 100644
--- a/lib/iscsi/conn.c
+++ b/lib/iscsi/conn.c
@@ -1257,6 +1257,21 @@ spdk_iscsi_conn_handle_nop(struct spdk_iscsi_conn *conn)
 	}
 }
 
+static bool
+iscsi_is_free_pdu_deferred(struct spdk_iscsi_pdu *pdu)
+{
+	if (pdu == NULL) {
+		return false;
+	}
+
+	if (pdu->bhs.opcode == ISCSI_OP_R2T ||
+	    pdu->bhs.opcode == ISCSI_OP_SCSI_DATAIN) {
+		return true;
+	}
+
+	return false;
+}
+
 /**
  * \brief Makes one attempt to flush response PDUs back to the initiator.
  *
@@ -1355,7 +1370,7 @@ iscsi_conn_flush_pdus_internal(struct spdk_iscsi_conn *conn)
 		TAILQ_REMOVE(&completed_pdus_list, pdu, tailq);
 		if ((conn->full_feature) &&
 		    (conn->sess->ErrorRecoveryLevel >= 1) &&
-		    spdk_iscsi_is_deferred_free_pdu(pdu)) {
+		    iscsi_is_free_pdu_deferred(pdu)) {
 			SPDK_DEBUGLOG(SPDK_LOG_ISCSI, "stat_sn=%d\n",
 				      from_be32(&pdu->bhs.stat_sn));
 			TAILQ_INSERT_TAIL(&conn->snack_pdu_list, pdu,
diff --git a/lib/iscsi/iscsi.c b/lib/iscsi/iscsi.c
index 23f82b45e4..578ae4d604 100644
--- a/lib/iscsi/iscsi.c
+++ b/lib/iscsi/iscsi.c
@@ -4961,17 +4961,3 @@ spdk_iscsi_handle_incoming_pdus(struct spdk_iscsi_conn *conn)
 
 	return i;
 }
-
-bool spdk_iscsi_is_deferred_free_pdu(struct spdk_iscsi_pdu *pdu)
-{
-	if (pdu == NULL) {
-		return false;
-	}
-
-	if (pdu->bhs.opcode == ISCSI_OP_R2T ||
-	    pdu->bhs.opcode == ISCSI_OP_SCSI_DATAIN) {
-		return true;
-	}
-
-	return false;
-}
diff --git a/lib/iscsi/iscsi.h b/lib/iscsi/iscsi.h
index 352a3e43c1..d3a55836f9 100644
--- a/lib/iscsi/iscsi.h
+++ b/lib/iscsi/iscsi.h
@@ -427,7 +427,6 @@ void spdk_clear_all_transfer_task(struct spdk_iscsi_conn *conn,
 				  struct spdk_scsi_lun *lun,
 				  struct spdk_iscsi_pdu *pdu);
 bool spdk_del_transfer_task(struct spdk_iscsi_conn *conn, uint32_t CmdSN);
-bool spdk_iscsi_is_deferred_free_pdu(struct spdk_iscsi_pdu *pdu);
 
 uint32_t spdk_iscsi_pdu_calc_header_digest(struct spdk_iscsi_pdu *pdu);
 uint32_t spdk_iscsi_pdu_calc_data_digest(struct spdk_iscsi_pdu *pdu);
diff --git a/test/unit/lib/iscsi/conn.c/conn_ut.c b/test/unit/lib/iscsi/conn.c/conn_ut.c
index 61644f4ab5..37ba3e1b1b 100644
--- a/test/unit/lib/iscsi/conn.c/conn_ut.c
+++ b/test/unit/lib/iscsi/conn.c/conn_ut.c
@@ -153,9 +153,6 @@ DEFINE_STUB(spdk_iscsi_build_iovs, int,
 	     struct spdk_iscsi_pdu *pdu, uint32_t *mapped_length),
 	    0);
 
-DEFINE_STUB(spdk_iscsi_is_deferred_free_pdu, bool,
-	    (struct spdk_iscsi_pdu *pdu), false);
-
 DEFINE_STUB_V(spdk_iscsi_task_response,
 	      (struct spdk_iscsi_conn *conn, struct spdk_iscsi_task *task));