diff --git a/include/bl31/runtime_svc.h b/include/bl31/runtime_svc.h
index f3543d4..2d84986 100644
--- a/include/bl31/runtime_svc.h
+++ b/include/bl31/runtime_svc.h
@@ -264,7 +264,7 @@
 /*******************************************************************************
  * Function & variable prototypes
  ******************************************************************************/
-void runtime_svc_init();
+void runtime_svc_init(void);
 extern uint64_t __RT_SVC_DESCS_START__;
 extern uint64_t __RT_SVC_DESCS_END__;
 void init_crash_reporting(void);