diff --git a/cli/smartcontract/smart_contract.go b/cli/smartcontract/smart_contract.go
index 10ca9c2cf..fe8b15a6c 100644
--- a/cli/smartcontract/smart_contract.go
+++ b/cli/smartcontract/smart_contract.go
@@ -427,7 +427,7 @@ func invokeInternal(ctx *cli.Context, signAndPush bool) error {
 		for i, c := range args[cosignersStart:] {
 			cosigner, err := parseCosigner(c)
 			if err != nil {
-				return cli.NewExitError(fmt.Errorf("failed to parse cosigner #%d: %v", i+cosignersStart+1, err), 1)
+				return cli.NewExitError(fmt.Errorf("failed to parse cosigner #%d: %v", i+1, err), 1)
 			}
 			cosigners = append(cosigners, cosigner)
 		}
@@ -692,7 +692,7 @@ func parseCosigner(c string) (transaction.Cosigner, error) {
 		err error
 		res = transaction.Cosigner{}
 	)
-	data := strings.SplitN(strings.ToLower(c), ":", 2)
+	data := strings.SplitN(c, ":", 2)
 	s := data[0]
 	if len(s) == 2*util.Uint160Size+2 && s[0:2] == "0x" {
 		s = s[2:]