diff --git a/core/types/l2trace.go b/core/types/l2trace.go
index f883238b2e7a..3b4ba75e814d 100644
--- a/core/types/l2trace.go
+++ b/core/types/l2trace.go
@@ -103,7 +103,7 @@ type ExtraData struct {
 	// Indicate the call succeeds or not for CALL/CREATE op
 	CallFailed bool `json:"callFailed,omitempty"`
 	// CALL | CALLCODE | DELEGATECALL | STATICCALL: [tx.to address’s code, stack.nth_last(1) address’s code]
-	CodeList [][]byte `json:"codeList,omitempty"`
+	CodeList []string `json:"codeList,omitempty"`
 	// SSTORE | SLOAD: [storageProof]
 	// SELFDESTRUCT: [contract address’s account, stack.nth_last(0) address’s account]
 	// SELFBALANCE: [contract address’s account]
diff --git a/core/vm/logger_trace.go b/core/vm/logger_trace.go
index 0e2e1abe9e68..7891499c01fd 100644
--- a/core/vm/logger_trace.go
+++ b/core/vm/logger_trace.go
@@ -32,7 +32,7 @@ func traceToAddressCode(l *StructLogger, scope *ScopeContext, extraData *types.E
 		return nil
 	}
 	code := l.env.StateDB.GetCode(*l.env.To)
-	extraData.CodeList = append(extraData.CodeList, code)
+	extraData.CodeList = append(extraData.CodeList, hexutil.Encode(code))
 	return nil
 }
 
@@ -45,7 +45,7 @@ func traceLastNAddressCode(n int) traceFunc {
 		}
 		address := common.Address(stack.data[stack.len()-1-n].Bytes20())
 		code := l.env.StateDB.GetCode(address)
-		extraData.CodeList = append(extraData.CodeList, code)
+		extraData.CodeList = append(extraData.CodeList, hexutil.Encode(code))
 		return nil
 	}
 }