diff --git a/lib/modules/blockchain_process/simulator.js b/lib/modules/blockchain_process/simulator.js
index 2206af47..a47fd731 100644
--- a/lib/modules/blockchain_process/simulator.js
+++ b/lib/modules/blockchain_process/simulator.js
@@ -63,7 +63,7 @@ class Simulator {
     // Setting up network id for simulator from blockchainConfig or options.
     // Otherwise ganache-cli would make random network id.
     let networkId = this.blockchainConfig.networkId || options.networkId;
-    if (typeof networkId != 'undefined') {
+    if (networkId) { // Don't handle networkId=="0" because it is not a valid networkId for ganache-cli.
       cmds.push("--networkId " + networkId);
     }