diff --git a/include/lib/extensions/trf.h b/include/lib/extensions/trf.h
index 18f17f3..a440abd 100644
--- a/include/lib/extensions/trf.h
+++ b/include/lib/extensions/trf.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2021, Arm Limited. All rights reserved.
+ * Copyright (c) 2021-2023, Arm Limited. All rights reserved.
  *
  * SPDX-License-Identifier: BSD-3-Clause
  */
@@ -7,6 +7,12 @@
 #ifndef TRF_H
 #define TRF_H
 
+#if ENABLE_TRF_FOR_NS
 void trf_enable(void);
+#else
+void trf_enable(void)
+{
+}
+#endif /* ENABLE_TRF_FOR_NS */
 
 #endif /* TRF_H */