diff --git a/pkg/geth/contract.go b/pkg/geth/contract.go
index ed4c9999..8813f545 100644
--- a/pkg/geth/contract.go
+++ b/pkg/geth/contract.go
@@ -19,7 +19,12 @@ func (blockchain *Blockchain) FetchContractData(abiJSON string, address string,
 	if err != nil {
 		return err
 	}
-	input, err := parsed.Pack(method, methodArg)
+	var input []byte
+	if methodArg != nil {
+		input, err = parsed.Pack(method, methodArg)
+	} else {
+		input, err = parsed.Pack(method)
+	}
 	if err != nil {
 		return err
 	}