diff --git a/bl31/aarch64/runtime_exceptions.S b/bl31/aarch64/runtime_exceptions.S
index e3673f0..97ca956 100644
--- a/bl31/aarch64/runtime_exceptions.S
+++ b/bl31/aarch64/runtime_exceptions.S
@@ -125,6 +125,9 @@
 	/* Restore the reference to the 'handle' i.e. SP_EL3 */
 	mov	x2, x20
 
+	/*  x3 will point to a cookie (not used now) */
+	mov	x3, xzr
+
 	/* Call the interrupt type handler */
 	blr	x21