diff --git a/protocols/service/attestation/packed-c/opcodes.h b/protocols/service/attestation/packed-c/opcodes.h
new file mode 100644
index 0000000..62a7617
--- /dev/null
+++ b/protocols/service/attestation/packed-c/opcodes.h
@@ -0,0 +1,16 @@
+/*
+ * Copyright (c) 2021, Arm Limited and Contributors. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#ifndef TS_ATTESTATION_OPCODES_H
+#define TS_ATTESTATION_OPCODES_H
+
+/* C/C++ definition of attestation service opcodes
+ */
+#define TS_ATTESTATION_OPCODE_NOP                   (0x0000)
+#define TS_ATTESTATION_OPCODE_GET_TOKEN             (0x0001)
+#define TS_ATTESTATION_OPCODE_GET_TOKEN_SIZE        (0x0002)
+
+#endif /* TS_ATTESTATION_OPCODES_H */