diff --git a/plat/arm/css/common/aarch64/css_helpers.S b/plat/arm/css/common/aarch64/css_helpers.S
index 0cf8f86..59d9206 100644
--- a/plat/arm/css/common/aarch64/css_helpers.S
+++ b/plat/arm/css/common/aarch64/css_helpers.S
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2013-2016, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2013-2017, ARM Limited and Contributors. All rights reserved.
  *
  * SPDX-License-Identifier: BSD-3-Clause
  */
@@ -88,9 +88,26 @@
 	 * cpu (applicable ony after a cold boot)
 	 * -----------------------------------------------------
 	 */
+#if CSS_USE_SCMI_SDS_DRIVER
 func plat_is_my_cpu_primary
 	mov	x9, x30
 	bl	plat_my_core_pos
+	mov	x4, x0
+	bl	sds_get_primary_cpu_id
+	/* Check for error */
+	mov	x1, #0xffffffff
+	cmp	x0, x1
+	b.eq	1f
+	cmp	x0, x4
+	cset	w0, eq
+	ret	x9
+1:
+	no_ret	plat_panic_handler
+endfunc plat_is_my_cpu_primary
+#else
+func plat_is_my_cpu_primary
+	mov	x9, x30
+	bl	plat_my_core_pos
 	ldr	x1, =SCP_BOOT_CFG_ADDR
 	ldr	x1, [x1]
 	ubfx	x1, x1, #PLAT_CSS_PRIMARY_CPU_SHIFT, \
@@ -99,3 +116,4 @@
 	cset	w0, eq
 	ret	x9
 endfunc plat_is_my_cpu_primary
+#endif