diff --git a/lib/tests/include/tests/t_api.h b/lib/tests/include/tests/t_api.h
index 6b078e99ae..7ac1eb81f5 100644
--- a/lib/tests/include/tests/t_api.h
+++ b/lib/tests/include/tests/t_api.h
@@ -51,7 +51,7 @@
 #define	T_ARG(n)	(*(av + (n)))
 
 
-typedef	void (*PFV)();
+typedef	void (*PFV)(void);
 
 typedef struct {
 	PFV	pfv;