diff --git a/assembly/vm-mock/env.ts b/assembly/vm-mock/env.ts
index eb238e96..614b16a0 100644
--- a/assembly/vm-mock/env.ts
+++ b/assembly/vm-mock/env.ts
@@ -19,6 +19,9 @@
 @external("massa", "assembly_script_mock_call")
 export declare function mockScCall(value: StaticArray<u8>): void;
 
+@external("massa", "assembly_script_set_chain_id")
+export declare function mockSetChainId(value: number): void;
+
 /**
  * Add a new smart contract address to the ledger
  *
diff --git a/vm-mock/vm.js b/vm-mock/vm.js
index 97b6aef5..43aa62ad 100644
--- a/vm-mock/vm.js
+++ b/vm-mock/vm.js
@@ -87,6 +87,7 @@ function resetLedger() {
 let webModule;
 
 const scCallMockStack = [];
+const chainIdMockStack = [];
 
 /**
  * Create a mock vm to simulate calls and responses of Massa WebAssembly sdk.
@@ -774,6 +775,17 @@ export default function createMockedABI(
         const hash = sha3.keccak256.arrayBuffer(data);
         return newArrayBuffer(hash);
       },
+      assembly_script_set_chain_id(value) {
+        chainIdMockStack.push(value);
+      },
+      assembly_script_chain_id() {
+        if (chainIdMockStack.length) {
+          return chainIdMockStack.shift();
+        }
+        throw new Error(
+          `No mock defined for chain id".`,
+        );
+      },
     },
   };