diff --git a/packages/types/src/type/ContractInfo.ts b/packages/types/src/type/ContractInfo.ts
index e7a59de22f..4164d5ea22 100644
--- a/packages/types/src/type/ContractInfo.ts
+++ b/packages/types/src/type/ContractInfo.ts
@@ -9,7 +9,7 @@ import Bytes from '../primitive/Bytes';
 import Enum from '../codec/Enum';
 import Struct from '../codec/Struct';
 import Hash from '../primitive/Hash';
-import U64 from '../primitive/U64';
+import U32 from '../primitive/U32';
 import Balance from './Balance';
 import BlockNumber from './BlockNumber';
 import CodeHash from './CodeHash';
@@ -21,7 +21,7 @@ export class AliveContractInfo extends Struct {
   constructor (value?: any) {
     super({
       trieId: TrieId,
-      storageSize: U64,
+      storageSize: U32,
       codeHash: CodeHash,
       rentAllowance: Balance,
       deductBlock: BlockNumber,
@@ -45,8 +45,8 @@ export class AliveContractInfo extends Struct {
     return this.get('rentAllowance') as Balance;
   }
 
-  get storageSize (): U64 {
-    return this.get('storageSize') as U64;
+  get storageSize (): U32 {
+    return this.get('storageSize') as U32;
   }
 
   get trieId (): TrieId {