diff --git a/spm/cactus/cactus.h b/spm/cactus/cactus.h
index 0b06eb2..cbf2dcb 100644
--- a/spm/cactus/cactus.h
+++ b/spm/cactus/cactus.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2017, Arm Limited. All rights reserved.
+ * Copyright (c) 2017-2020, Arm Limited. All rights reserved.
  *
  * SPDX-License-Identifier: BSD-3-Clause
  */
@@ -26,4 +26,11 @@
 #define CACTUS_BSS_START	((uintptr_t)&__BSS_START__)
 #define CACTUS_BSS_END		((uintptr_t)&__BSS_END__)
 
+enum stdout_route {
+	PL011_AS_STDOUT = 0,
+	HVC_CALL_AS_STDOUT,
+};
+
+void set_putc_impl(enum stdout_route);
+
 #endif /* __CACTUS_H__ */