diff --git a/examples/nfs4-cat-talloc.c b/examples/nfs4-cat-talloc.c
index d7fe5da..1a6e183 100644
--- a/examples/nfs4-cat-talloc.c
+++ b/examples/nfs4-cat-talloc.c
@@ -680,7 +680,7 @@ void setclientid_cb(struct rpc_context *rpc, int status, void *data,
 /*
  * NULL procedure for the callback protocol.
  */
-static int cb_null_proc(struct rpc_context *rpc, struct rpc_msg *call)
+static int cb_null_proc(struct rpc_context *rpc, struct rpc_msg *call, void *opaque)
 {
         rpc_send_reply(rpc, call, NULL, (zdrproc_t)zdr_void, 0);
 
@@ -691,7 +691,7 @@ static int cb_null_proc(struct rpc_context *rpc, struct rpc_msg *call)
  * CB_COMPOUND procedure for the callback protocol.
  * This is where the server will inform us about lease breaks and similar.
  */
-static int cb_compound_proc(struct rpc_context *rpc, struct rpc_msg *call)
+static int cb_compound_proc(struct rpc_context *rpc, struct rpc_msg *call, void *opaque)
 {
         CB_COMPOUND4args *args = call->body.cbody.args;
 
diff --git a/examples/nfs4-cat.c b/examples/nfs4-cat.c
index b442a61..a5a90cd 100644
--- a/examples/nfs4-cat.c
+++ b/examples/nfs4-cat.c
@@ -682,7 +682,7 @@ void setclientid_cb(struct rpc_context *rpc, int status, void *data,
 /*
  * NULL procedure for the callback protocol.
  */
-static int cb_null_proc(struct rpc_context *rpc, struct rpc_msg *call)
+static int cb_null_proc(struct rpc_context *rpc, struct rpc_msg *call, void *opaque)
 {
         rpc_send_reply(rpc, call, NULL, (zdrproc_t)zdr_void, 0);
 
@@ -693,7 +693,7 @@ static int cb_null_proc(struct rpc_context *rpc, struct rpc_msg *call)
  * CB_COMPOUND procedure for the callback protocol.
  * This is where the server will inform us about lease breaks and similar.
  */
-static int cb_compound_proc(struct rpc_context *rpc, struct rpc_msg *call)
+static int cb_compound_proc(struct rpc_context *rpc, struct rpc_msg *call, void *opaque)
 {
         CB_COMPOUND4args *args = call->body.cbody.args;
 
diff --git a/examples/portmap-server.c b/examples/portmap-server.c
index f7b5514..5a42e41 100644
--- a/examples/portmap-server.c
+++ b/examples/portmap-server.c
@@ -248,7 +248,7 @@ void map_remove(int prog, int vers, char *netid)
  * It is used by clients, and rpcinfo, to "ping" a service and verify that
  * the service is available and that it does support the indicated version.
  */
-static int pmap2_null_proc(struct rpc_context *rpc, struct rpc_msg *call)
+static int pmap2_null_proc(struct rpc_context *rpc, struct rpc_msg *call, void *opaque)
 {
         rpc_send_reply(rpc, call, NULL, (zdrproc_t)zdr_void, 0);
 
@@ -262,7 +262,7 @@ static int pmap2_null_proc(struct rpc_context *rpc, struct rpc_msg *call)
  * and portmapper returns which port that service is available on,
  * (or 0 if no such program is registered.)
  */
-static int pmap2_getport_proc(struct rpc_context *rpc, struct rpc_msg *call)
+static int pmap2_getport_proc(struct rpc_context *rpc, struct rpc_msg *call, void *opaque)
 {
         PMAP2GETPORTargs *args = call->body.cbody.args;
         struct mapping *tmp;
@@ -290,7 +290,7 @@ static int pmap2_getport_proc(struct rpc_context *rpc, struct rpc_msg *call)
  * This RPC returns a list of all endpoints that are registered with
  * portmapper.
  */
-static int pmap2_dump_proc(struct rpc_context *rpc, struct rpc_msg *call)
+static int pmap2_dump_proc(struct rpc_context *rpc, struct rpc_msg *call, void *opaque)
 {
         PMAP2DUMPres reply;
         struct mapping *tmp;
@@ -336,7 +336,7 @@ static int pmap2_dump_proc(struct rpc_context *rpc, struct rpc_msg *call)
  * v2 SET
  * This procedure is used to register and endpoint with portmapper.
  */
-static int pmap2_set_proc(struct rpc_context *rpc, struct rpc_msg *call)
+static int pmap2_set_proc(struct rpc_context *rpc, struct rpc_msg *call, void *opaque)
 {
         PMAP2GETPORTargs *args = call->body.cbody.args;
         char *prot;
@@ -369,7 +369,7 @@ static int pmap2_set_proc(struct rpc_context *rpc, struct rpc_msg *call)
  * This procedure is used to remove a registration from portmappers
  * list of endpoints.
  */
-static int pmap2_unset_proc(struct rpc_context *rpc, struct rpc_msg *call)
+static int pmap2_unset_proc(struct rpc_context *rpc, struct rpc_msg *call, void *opaque)
 {
         PMAP2GETPORTargs *args = call->body.cbody.args;
         char *prot;
@@ -424,7 +424,7 @@ struct service_proc pmap2_pt[] = {
  * It is used by clients, and rpcinfo, to "ping" a service and verify that
  * the service is available and that it does support the indicated version.
  */
-static int pmap3_null_proc(struct rpc_context *rpc, struct rpc_msg *call)
+static int pmap3_null_proc(struct rpc_context *rpc, struct rpc_msg *call, void *opaque)
 {
         rpc_send_reply(rpc, call, NULL, (zdrproc_t)zdr_void, 0);
 
@@ -436,7 +436,7 @@ static int pmap3_null_proc(struct rpc_context *rpc, struct rpc_msg *call)
  * This RPC returns a list of all endpoints that are registered with
  * portmapper.
  */
-static int pmap3_dump_proc(struct rpc_context *rpc, struct rpc_msg *call)
+static int pmap3_dump_proc(struct rpc_context *rpc, struct rpc_msg *call, void *opaque)
 {
         PMAP3DUMPres reply;
         struct mapping *tmp;
diff --git a/include/nfsc/libnfs-raw.h b/include/nfsc/libnfs-raw.h
index 48df800..242bd56 100644
--- a/include/nfsc/libnfs-raw.h
+++ b/include/nfsc/libnfs-raw.h
@@ -114,13 +114,14 @@ EXTERN struct rpc_context *rpc_init_server_context(int s);
  * !0:  An abnormal error has occured. It is unrecoverable and the only
  *      meaningful action is to tear down the connection to the server.
  */
-typedef int (*service_fn)(struct rpc_context *rpc, struct rpc_msg *call);
+typedef int (*service_fn)(struct rpc_context *rpc, struct rpc_msg *call, void *opaque);
 
 struct service_proc {
         int proc;
         service_fn func;
         zdrproc_t decode_fn;
         int decode_buf_size;
+        void *opaque;
 };
 
 /*
diff --git a/lib/pdu.c b/lib/pdu.c
index a0d5525..a3285c5 100644
--- a/lib/pdu.c
+++ b/lib/pdu.c
@@ -497,7 +497,7 @@ static int rpc_process_call(struct rpc_context *rpc, ZDR *zdr)
                                               "call payload");
                                 return rpc_send_error_reply(rpc, &call, GARBAGE_ARGS, 0 ,0);
                         }
-                        return endpoint->procs[i].func(rpc, &call);
+                        return endpoint->procs[i].func(rpc, &call, endpoint->procs[i].opaque);
                 }
         }