diff --git a/services/std_svc/sdei/sdei_main.c b/services/std_svc/sdei/sdei_main.c
index 44178ed..f421831 100644
--- a/services/std_svc/sdei/sdei_main.c
+++ b/services/std_svc/sdei/sdei_main.c
@@ -35,8 +35,6 @@
 
 #define LOWEST_INTR_PRIORITY		0xff
 
-#define is_valid_affinity(_mpidr)	(plat_core_pos_by_mpidr(_mpidr) >= 0)
-
 CASSERT(PLAT_SDEI_CRITICAL_PRI < PLAT_SDEI_NORMAL_PRI,
 		sdei_critical_must_have_higher_priority);
 
@@ -262,7 +260,7 @@
 	/* Validate flags */
 	switch (flags) {
 	case SDEI_REGF_RM_PE:
-		if (!is_valid_affinity(mpidr))
+		if (!is_valid_mpidr(mpidr))
 			return SDEI_EINVAL;
 		break;
 	case SDEI_REGF_RM_ANY:
@@ -926,7 +924,7 @@
 		return SDEI_EINVAL;
 
 	/* Validate target */
-	if (plat_core_pos_by_mpidr(target_pe) < 0)
+	if (!is_valid_mpidr(target_pe))
 		return SDEI_EINVAL;
 
 	/* Raise SGI. Platform will validate target_pe */