diff --git a/package-lock.json b/package-lock.json
index a06af06..a96aa45 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -1,12 +1,12 @@
 {
   "name": "@orionprotocol/sdk",
-  "version": "0.20.42-rc4",
+  "version": "0.20.42-rc5",
   "lockfileVersion": 2,
   "requires": true,
   "packages": {
     "": {
       "name": "@orionprotocol/sdk",
-      "version": "0.20.42-rc4",
+      "version": "0.20.42-rc5",
       "hasInstallScript": true,
       "license": "ISC",
       "dependencies": {
diff --git a/package.json b/package.json
index 6ce7550..66512fb 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@orionprotocol/sdk",
-  "version": "0.20.42-rc4",
+  "version": "0.20.42-rc5",
   "description": "Orion Protocol SDK",
   "main": "./lib/index.cjs",
   "module": "./lib/index.js",
diff --git a/src/crypt/signOrder.ts b/src/crypt/signOrder.ts
index 7008935..013841b 100644
--- a/src/crypt/signOrder.ts
+++ b/src/crypt/signOrder.ts
@@ -55,8 +55,12 @@ export const signOrder = async (
     )),
     nonce,
     expiration,
-    secretHash,
-    targetChainId,
+    ...(targetChainId !== undefined
+      ? {
+        secretHash,
+        targetChainId
+      }
+      : {}),
     buySide: side === 'BUY' ? 1 : 0,
   };
 
diff --git a/src/types.ts b/src/types.ts
index 2fd40b0..8de284a 100644
--- a/src/types.ts
+++ b/src/types.ts
@@ -49,9 +49,9 @@ export type Order = {
   matcherFee: number // uint64
   nonce: number // uint64
   expiration: number // uint64
-  secretHash: string // uint64
   buySide: 0 | 1 // uint8, 1=buy, 0=sell
-  targetChainId: ethers.BigNumberish | undefined // uint64
+  secretHash?: string // uint64
+  targetChainId?: ethers.BigNumberish // uint64
 }
 
 export type LockOrder = {