diff --git a/include/plat/arm/common/plat_arm.h b/include/plat/arm/common/plat_arm.h
index 025a64f..45c099f 100644
--- a/include/plat/arm/common/plat_arm.h
+++ b/include/plat/arm/common/plat_arm.h
@@ -262,7 +262,7 @@
  * Optional functions in ARM standard platforms
  */
 void plat_arm_override_gicr_frames(const uintptr_t *plat_gicr_frames);
-int arm_get_rotpk_info(void **key_ptr, unsigned int *key_len,
+int arm_get_rotpk_info(void *cookie, void **key_ptr, unsigned int *key_len,
 	unsigned int *flags);
 int arm_get_rotpk_info_regs(void **key_ptr, unsigned int *key_len,
 	unsigned int *flags);