diff --git a/modules/cellframe-sdk/common/src/wrapping_dap_chain_datum_tx.c b/modules/cellframe-sdk/common/src/wrapping_dap_chain_datum_tx.c
index dbfbcce65e0e91f44acb1f9f048166429342c9bf..cac89c44ba37360b252ce5a44936fb844c0daf0c 100644
--- a/modules/cellframe-sdk/common/src/wrapping_dap_chain_datum_tx.c
+++ b/modules/cellframe-sdk/common/src/wrapping_dap_chain_datum_tx.c
@@ -182,7 +182,7 @@ PyObject *dap_chain_datum_tx_add_sign_item_py(PyObject *self, PyObject *args){
 
 PyObject *dap_chain_datum_tx_verify_sign_py(PyObject *self, PyObject *args){
     (void)args;
-    int res = dap_chain_datum_tx_verify_sign(((PyDapChainDatumTxObject*)self)->datum_tx);
+    int res = dap_chain_datum_tx_verify_sign(((PyDapChainDatumTxObject*)self)->datum_tx, 0);
     return PyLong_FromLong(res);
 }