diff --git a/packages/config/src/chains.ts b/packages/config/src/chains.ts
index 0dc39e04..94ae2818 100644
--- a/packages/config/src/chains.ts
+++ b/packages/config/src/chains.ts
@@ -909,11 +909,9 @@ export const laosAlphanet = new EvmParachain({
     '0x324e69fa1a64c0b3badec0016aca64878bc2f4b6146e6da26c7aaddee21947f7',
   key: 'laos-alphanet',
   name: 'Laos Alphanet',
-  id: 0, // TODO
   isTestChain: true,
   nativeAsset: maos,
   parachainId: 4001,
-  rpc: 'https://rpc.laosalphanet.gorengine.com', // TODO
   ss58Format: 42,
   ws: ['wss://rpc.laosalphanet.gorengine.com'],
 });
diff --git a/packages/types/src/chain/parachain/EvmParachain.ts b/packages/types/src/chain/parachain/EvmParachain.ts
index 60ef2789..1e3a7b33 100644
--- a/packages/types/src/chain/parachain/EvmParachain.ts
+++ b/packages/types/src/chain/parachain/EvmParachain.ts
@@ -4,14 +4,26 @@ import { getViemChain } from '../Chain.utils';
 import { EvmChain } from '../EvmChain';
 import { Parachain, type ParachainConstructorParams } from './Parachain';
 
-export interface EvmParachainConstructorParams
-  extends ParachainConstructorParams {
-  id: number;
-  rpc: string;
+interface EvmParachainConstructorParams extends ParachainConstructorParams {
   isEvmSigner?: boolean;
   contracts?: Contracts;
 }
 
+type EvmParachainConstructorParamsForEvmSigner =
+  EvmParachainConstructorParams & {
+    id: number;
+    rpc: string;
+  };
+
+type EvmParachainConstructorParamsForNonEvmSigner = Omit<
+  EvmParachainConstructorParams,
+  'id' | 'rpc'
+>;
+
+type EvmParachainConstructorParamsConditional =
+  | (EvmParachainConstructorParamsForEvmSigner & { isEvmSigner: true })
+  | (EvmParachainConstructorParamsForNonEvmSigner & { isEvmSigner?: false });
+
 type Contracts = {
   Batch?: Address;
   XcmUtils?: Address;
@@ -39,19 +51,13 @@ export class EvmParachain extends Parachain {
     return obj instanceof EvmParachain || obj instanceof EvmChain;
   }
 
-  constructor({
-    id,
-    rpc,
-    isEvmSigner = false,
-    contracts,
-    ...others
-  }: EvmParachainConstructorParams) {
-    super(others);
-
-    this.contracts = contracts;
-    this.id = id;
-    this.rpc = rpc;
-    this.isEvmSigner = isEvmSigner;
+  constructor(params: EvmParachainConstructorParamsConditional) {
+    super(params);
+
+    this.contracts = params.contracts;
+    this.id = 'id' in params ? params.id : 0;
+    this.rpc = 'rpc' in params ? params.rpc : '';
+    this.isEvmSigner = params.isEvmSigner ?? false;
   }
 
   getViemChain(): Chain {