diff --git a/include/plat/arm/common/arm_fconf_getter.h b/include/plat/arm/common/arm_fconf_getter.h
index 28913a43f3125f57da9e60f4ac1a423d400afeee..8fd8c7ada4b6e7214431ce7ce5975f3c23f8d4cb 100644
--- a/include/plat/arm/common/arm_fconf_getter.h
+++ b/include/plat/arm/common/arm_fconf_getter.h
@@ -7,10 +7,15 @@
 #ifndef ARM_FCONF_GETTER
 #define ARM_FCONF_GETTER
 
+#include <assert.h>
+
 #include <lib/fconf/fconf.h>
 
 /* ARM io policies */
-#define arm__io_policies_getter(id)	&policies[id]
+#define arm__io_policies_getter(id) __extension__ ({	\
+	assert((id) < MAX_NUMBER_IDS);			\
+	&policies[id];					\
+})
 
 struct plat_io_policy {
 	uintptr_t *dev_handle;
diff --git a/plat/arm/common/arm_io_storage.c b/plat/arm/common/arm_io_storage.c
index 6fcfbd6fbcc32bbbe6ec160aab8dc30d79262cd7..34b4101e1a0bda96b01074034a2a7f2a6a4e1b61 100644
--- a/plat/arm/common/arm_io_storage.c
+++ b/plat/arm/common/arm_io_storage.c
@@ -4,8 +4,6 @@
  * SPDX-License-Identifier: BSD-3-Clause
  */
 
-#include <assert.h>
-
 #include <common/debug.h>
 #include <drivers/io/io_driver.h>
 #include <drivers/io/io_fip.h>
@@ -116,8 +114,6 @@ int plat_get_image_source(unsigned int image_id, uintptr_t *dev_handle,
 	int result;
 	const struct plat_io_policy *policy;
 
-	assert(image_id < MAX_NUMBER_IDS);
-
 	policy = FCONF_GET_PROPERTY(arm, io_policies, image_id);
 	result = policy->check(policy->image_spec);
 	if (result == 0) {