diff --git a/plat/arm/board/tc/region_defs.h b/plat/arm/board/tc/region_defs.h
new file mode 100644
index 0000000..d3dfd13
--- /dev/null
+++ b/plat/arm/board/tc/region_defs.h
@@ -0,0 +1,12 @@
+/*
+ * Copyright (c) 2022, Arm Ltd. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#ifndef REGION_DEFS_H
+#define REGION_DEFS_H
+
+#define PSA_INITIAL_ATTEST_TOKEN_MAX_SIZE   0x800
+
+#endif /* REGION_DEFS_H */