diff --git a/buffet/states/error_codes.h b/buffet/states/error_codes.h
new file mode 100644
index 0000000..2298741
--- /dev/null
+++ b/buffet/states/error_codes.h
@@ -0,0 +1,25 @@
+// Copyright 2014 The Chromium OS Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef BUFFET_STATES_ERROR_CODES_H_
+#define BUFFET_STATES_ERROR_CODES_H_
+
+namespace buffet {
+namespace errors {
+namespace state {
+
+// Error domain for state definitions.
+extern const char kDomain[];
+
+// State-specific error codes.
+extern const char kPackageNameMissing[];
+extern const char kPropertyNameMissing[];
+extern const char kPropertyNotDefined[];
+extern const char kPropertyRedefinition[];
+
+}  // namespace state
+}  // namespace errors
+}  // namespace buffet
+
+#endif  // BUFFET_STATES_ERROR_CODES_H_