diff --git a/lib/optee/optee_utils.c b/lib/optee/optee_utils.c
index f7392fd..2a40793 100644
--- a/lib/optee/optee_utils.c
+++ b/lib/optee/optee_utils.c
@@ -176,7 +176,7 @@
 	 */
 	if (!tee_validate_header(header)) {
 		INFO("Invalid OPTEE header, set legacy mode.\n");
-#ifdef AARCH64
+#ifdef __aarch64__
 		header_ep->args.arg0 = MODE_RW_64;
 #else
 		header_ep->args.arg0 = MODE_RW_32;
@@ -222,7 +222,7 @@
 	if (header->arch == 0) {
 		header_ep->args.arg0 = MODE_RW_32;
 	} else {
-#ifdef AARCH64
+#ifdef __aarch64__
 		header_ep->args.arg0 = MODE_RW_64;
 #else
 		ERROR("Cannot boot an AArch64 OP-TEE\n");