diff --git a/interface/vchiq_arm/vchiq_lib.c b/interface/vchiq_arm/vchiq_lib.c
index 133d5ca65..7a2dae5d2 100755
--- a/interface/vchiq_arm/vchiq_lib.c
+++ b/interface/vchiq_arm/vchiq_lib.c
@@ -537,7 +537,7 @@ vchiq_bulk_receive_handle(VCHIQ_SERVICE_HANDLE_T handle,
    int size,
    void *userdata,
    VCHIQ_BULK_MODE_T mode,
-   int (*copy_pagelist)())
+   int (*copy_pagelist)(char *vcptr, const struct pagelist_struct *pagelist))
 {
    VCHIQ_SERVICE_T *service = find_service_by_handle(handle);
    VCHIQ_QUEUE_BULK_TRANSFER_T args;
diff --git a/interface/vmcs_host/vc_vchi_gpuserv.h b/interface/vmcs_host/vc_vchi_gpuserv.h
index fc0bfee98..ce6cb58de 100755
--- a/interface/vmcs_host/vc_vchi_gpuserv.h
+++ b/interface/vmcs_host/vc_vchi_gpuserv.h
@@ -58,7 +58,7 @@ struct sync_job_s {
 
 struct gpu_callback_s {
   // callback to call when complete (can be NULL)
-  void (*func)();
+  void (*func)(void*);
   void *cookie;
 };