diff --git a/core/vm/contracts.go b/core/vm/contracts.go
index e7a19a3b21..28394d4dd2 100644
--- a/core/vm/contracts.go
+++ b/core/vm/contracts.go
@@ -176,7 +176,7 @@ func (c *dataCopy) RequiredGas(input []byte) uint64 {
 	return uint64(len(input)+31)/32*params.IdentityPerWordGas + params.IdentityBaseGas
 }
 func (c *dataCopy) Run(in []byte) ([]byte, error) {
-	return in, nil
+	return common.CopyBytes(in), nil
 }
 
 // bigModExp implements a native big integer exponential modular operation.