diff --git a/modules/src/idf/idf_pkg.body b/modules/src/idf/idf_pkg.body
index 5d1260d75..cb6aa7b0d 100644
--- a/modules/src/idf/idf_pkg.body
+++ b/modules/src/idf/idf_pkg.body
@@ -93,7 +93,7 @@ void hash_stat(void)
 	print("End hash table tally\n");
 }
 
-void idfappfun(int (*fun)(), int opt)
+void idfappfun(int (*fun)(struct idf *, int), int opt)
 {
 	register int i;