diff --git a/bl31/interrupt_mgmt.c b/bl31/interrupt_mgmt.c
index 1a1cbc4..641d66a 100644
--- a/bl31/interrupt_mgmt.c
+++ b/bl31/interrupt_mgmt.c
@@ -78,7 +78,7 @@
  * routing model (expressed through the IRQ and FIQ bits) for a security state
  * which was stored through a call to 'set_routing_model()' earlier.
  ******************************************************************************/
-u_register_t get_scr_el3_from_routing_model(uint32_t security_state)
+u_register_t get_scr_el3_from_routing_model(size_t security_state)
 {
 	u_register_t scr_el3;