diff --git a/bonobo-activation/bonobo-activation-base-service.c b/bonobo-activation/bonobo-activation-base-service.c
index d274378..609b565 100644
--- a/bonobo-activation/bonobo-activation-base-service.c
+++ b/bonobo-activation/bonobo-activation-base-service.c
@@ -160,21 +160,24 @@ bonobo_activation_registration_iterate (const BonoboActivationBaseService *base_
 
 	for (link = registries; link; link = link->next) {
 		RegistryInfo *ri;
-		void (*func_ptr) ();
+		void (*func_ptr_2arg) (const BonoboActivationBaseServiceRegistry *, gpointer);
+		void (*func_ptr_4arg) (
+			const BonoboActivationBaseServiceRegistry *, const char *,
+			const BonoboActivationBaseService *, gpointer
+			);
 
 		ri = link->data;
 
-		func_ptr = *(gpointer *) ((guchar *) ri->registry + offset);
-
-		if (!func_ptr)
-			continue;
-
 		switch (nargs) {
 		case 4:
-			func_ptr (ri->registry, ior, base_service, ri->user_data);
+			func_ptr_4arg = *(gpointer *) ((guchar *) ri->registry + offset);
+			if (!func_ptr_4arg) continue;
+			func_ptr_4arg (ri->registry, ior, base_service, ri->user_data);
 			break;
 		case 2:
-			func_ptr (ri->registry, ri->user_data);
+			func_ptr_2arg = *(gpointer *) ((guchar *) ri->registry + offset);
+			if (!func_ptr_2arg) continue;
+			func_ptr_2arg (ri->registry, ri->user_data);
 			break;
 		}
 	}