diff --git a/core/vm/instructions.go b/core/vm/instructions.go
index 84855bf845..10ea09ed8b 100644
--- a/core/vm/instructions.go
+++ b/core/vm/instructions.go
@@ -516,6 +516,9 @@ func opSload(pc *uint64, evm *EVM, scope *ScopeContext) ([]byte, error) {
 }
 
 func opSstore(pc *uint64, evm *EVM, scope *ScopeContext) ([]byte, error) {
+	if evm.readOnly {
+		return nil, ErrWriteProtection
+	}
 	loc := scope.Stack.pop()
 	val := scope.Stack.pop()
 	evm.StateDB.SetState(scope.Contract.Address(), loc.Bytes32(), val.Bytes32())