diff --git a/javascript/packages/orchestrator/src/chainSpec.ts b/javascript/packages/orchestrator/src/chainSpec.ts
index 9332f7f4a..b05f0aac6 100644
--- a/javascript/packages/orchestrator/src/chainSpec.ts
+++ b/javascript/packages/orchestrator/src/chainSpec.ts
@@ -432,6 +432,11 @@ export async function addParachainToGenesis(
     else if (runtimeConfig.parachainsParas) {
       paras = runtimeConfig.parachainsParas.paras;
     }
+    // The config may not contain paras. Since chainspec allows to contain the RuntimeGenesisConfig patch we can inject it.
+    else {
+      runtimeConfig.paras = { paras: [] };
+      paras = runtimeConfig.paras.paras;
+    }
     if (paras) {
       const new_para = [
         parseInt(para_id),
@@ -622,11 +627,13 @@ function findAndReplaceConfig(obj1: any, obj2: any) {
 }
 
 export function getRuntimeConfig(chainSpec: any) {
-  const runtimeConfig =
+  // runtime_genesis_config is no longer in ChainSpec after rococo runtime rework (refer to: https://github.com/paritytech/polkadot-sdk/pull/1256)
+  // ChainSpec may contain a RuntimeGenesisConfigPatch
+  return (
+    chainSpec.genesis.runtimeGenesisConfigPatch ||
     chainSpec.genesis.runtime?.runtime_genesis_config ||
-    chainSpec.genesis.runtime;
-
-  return runtimeConfig;
+    chainSpec.genesis.runtime
+  );
 }
 
 export function readAndParseChainSpec(specPath: string) {