diff --git a/client/emv/cmdemv.c b/client/emv/cmdemv.c
index ec6aa2c3..9c96434b 100644
--- a/client/emv/cmdemv.c
+++ b/client/emv/cmdemv.c
@@ -334,8 +334,13 @@ bool ParamLoadFromJson(struct tlvdb *tlv) {
 		return false; 
 	}
 
-	// TODO: add search current path
-	root = json_load_file("./emv/defparams.json", 0, &error);
+	// current path + file name
+	const char *relfname = "emv/defparams.json"; 
+	char fname[strlen(get_my_executable_directory()) + strlen(relfname) + 1];
+	strcpy(fname, get_my_executable_directory());
+	strcat(fname, relfname);
+
+	root = json_load_file(fname, 0, &error);
 	if (!root) {
 		PrintAndLog("Load params: json error on line %d: %s", error.line, error.text);
 		return false; 
@@ -396,7 +401,7 @@ bool ParamLoadFromJson(struct tlvdb *tlv) {
 		uint8_t buf[251] = {0};
 		size_t buflen = 0;
 		
-		// here max length must be 4, but now tlv_tag_t is 2-byte var. so let it be 2 by now...  needs refactoring tlv_tag_t...
+		// here max length must be 4, but now tlv_tag_t is 2-byte var. so let it be 2 by now...  TODO: needs refactoring tlv_tag_t...
 		if (!HexToBuffer("TLV Error type:", tlvType, buf, 2, &buflen)) { 
 			json_decref(root);
 			return false;
@@ -425,6 +430,26 @@ bool ParamLoadFromJson(struct tlvdb *tlv) {
 	return true;
 }
 
+void ParamLoadDefaults(struct tlvdb *tlvRoot) {
+	//9F02:(Amount, authorized (Numeric)) len:6
+	TLV_ADD(0x9F02, "\x00\x00\x00\x00\x01\x00");
+	//9F1A:(Terminal Country Code) len:2
+	TLV_ADD(0x9F1A, "ru");
+	//5F2A:(Transaction Currency Code) len:2
+	// USD 840, EUR 978, RUR 810, RUB 643, RUR 810(old), UAH 980, AZN 031, n/a 999
+	TLV_ADD(0x5F2A, "\x09\x80");
+	//9A:(Transaction Date) len:3
+	TLV_ADD(0x9A,   "\x00\x00\x00");
+	//9C:(Transaction Type) len:1   |  00 => Goods and service #01 => Cash
+	TLV_ADD(0x9C,   "\x00");
+	// 9F37 Unpredictable Number len:4
+	TLV_ADD(0x9F37, "\x01\x02\x03\x04");
+	// 9F6A Unpredictable Number (MSD for UDOL) len:4
+	TLV_ADD(0x9F6A, "\x01\x02\x03\x04");
+	//9F66:(Terminal Transaction Qualifiers (TTQ)) len:4
+	TLV_ADD(0x9F66, "\x26\x00\x00\x00"); // qVSDC
+}
+
 int CmdHFEMVExec(const char *cmd) {
 	bool activateField = false;
 	bool showAPDU = false;
@@ -432,6 +457,7 @@ int CmdHFEMVExec(const char *cmd) {
 	bool forceSearch = false;
 	enum TransactionType TrType = TT_MSD;
 	bool GenACGPO = false;
+	bool paramLoadJSON = false;
 
 	uint8_t buf[APDU_RES_LEN] = {0};
 	size_t len = 0;
@@ -493,6 +519,10 @@ int CmdHFEMVExec(const char *cmd) {
 				case 'G':
 					GenACGPO = true;
 					break;
+				case 'j':
+				case 'J':
+					paramLoadJSON = true;
+					break;
 				default:
 					PrintAndLog("Unknown parameter '%c'", param_getchar_indx(cmd, 1, cmdp));
 					return 1;
@@ -559,7 +589,12 @@ int CmdHFEMVExec(const char *cmd) {
 	
 	PrintAndLog("\n* Init transaction parameters.");
 
-	ParamLoadFromJson(tlvRoot);
+	ParamLoadDefaults(tlvRoot);
+
+	if (paramLoadJSON) {
+		PrintAndLog("* * Transaction parameters loading from JSON...");
+		ParamLoadFromJson(tlvRoot);
+	}
 	
 	//9F66:(Terminal Transaction Qualifiers (TTQ)) len:4
 	char *qVSDC = "\x26\x00\x00\x00";
@@ -581,26 +616,9 @@ int CmdHFEMVExec(const char *cmd) {
 			TLV_ADD(0x9F66, qVSDC); // qVSDC (VISA CDA not enabled)
 			break;
 		default:
-			TLV_ADD(0x9F66, "\x26\x00\x00\x00"); // qVSDC
 			break;
 	}
 	
-	//9F02:(Amount, authorized (Numeric)) len:6
-	TLV_ADD(0x9F02, "\x00\x00\x00\x00\x01\x00");
-	//9F1A:(Terminal Country Code) len:2
-	TLV_ADD(0x9F1A, "ru");
-	//5F2A:(Transaction Currency Code) len:2
-	// USD 840, EUR 978, RUR 810, RUB 643, RUR 810(old), UAH 980, AZN 031, n/a 999
-	TLV_ADD(0x5F2A, "\x09\x80");
-	//9A:(Transaction Date) len:3
-	TLV_ADD(0x9A,   "\x00\x00\x00");
-	//9C:(Transaction Type) len:1   |  00 => Goods and service #01 => Cash
-	TLV_ADD(0x9C,   "\x00");
-	// 9F37 Unpredictable Number len:4
-	TLV_ADD(0x9F37, "\x01\x02\x03\x04");
-	// 9F6A Unpredictable Number (MSD for UDOL) len:4
-	TLV_ADD(0x9F6A, "\x01\x02\x03\x04");
-
 	TLVPrintFromTLV(tlvRoot); // TODO delete!!!
 	
 	PrintAndLog("\n* Calc PDOL.");
diff --git a/client/emv/defparams.json b/client/emv/defparams.json
index af65e30c..47f1c8a1 100644
--- a/client/emv/defparams.json
+++ b/client/emv/defparams.json
@@ -51,8 +51,8 @@
   {
     "name": "Unpredictable Number (MSD for UDOL)",
     "type": "9F 6A",
-    "value": "01 02 03 04",
+    "value": "01 02 03 05",
     "length": 4,
     "hint": "4 byte random number"
   }
-]
\ No newline at end of file
+]
diff --git a/client/emv/tlv.c b/client/emv/tlv.c
index 08e09f23..776fdeed 100644
--- a/client/emv/tlv.c
+++ b/client/emv/tlv.c
@@ -376,12 +376,12 @@ void tlvdb_change_or_add_node(struct tlvdb *tlvdb, tlv_tag_t tag, size_t len, co
 		tnewelm->next = telm->next;
 		tnewelm->parent = telm->parent;
 		
-		// if elm stays 1st in children link
+		// if telm stayed first in children chain
 		if (telm->parent && telm->parent->children == telm) {
 			telm->parent->children = tnewelm;
 		}
 		
-		// if elm have prev element
+		// if telm have previous element
 		if (telm != tlvdb) {
 			// elm in root
 			struct tlvdb *celm = tlvdb;
@@ -398,7 +398,7 @@ void tlvdb_change_or_add_node(struct tlvdb *tlvdb, tlv_tag_t tag, size_t len, co
 			}
 		}
 		
-		// free old element
+		// free old element with childrens
 		telm->next = NULL;
 		tlvdb_free(telm);
 	}