diff --git a/include/lib/libc/aarch64/stdlib_.h b/include/lib/libc/aarch64/stdlib_.h
new file mode 100644
index 0000000..3612c99
--- /dev/null
+++ b/include/lib/libc/aarch64/stdlib_.h
@@ -0,0 +1,13 @@
+/*
+ * Copyright (c) 2018, ARM Limited and Contributors. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#ifndef SIZET_
+typedef unsigned long size_t;
+#define SIZET_
+#endif
+
+#define EXIT_FAILURE 1
+#define EXIT_SUCCESS 0