diff --git a/isisd/isis_circuit.c b/isisd/isis_circuit.c
index c5812a658d..0ea6c3d453 100644
--- a/isisd/isis_circuit.c
+++ b/isisd/isis_circuit.c
@@ -606,6 +606,18 @@ isis_circuit_stream(struct isis_circuit *circuit, struct stream **stream)
     }
 }
 
+void
+isis_circuit_prepare (struct isis_circuit *circuit)
+{
+#ifdef GNU_LINUX
+  THREAD_READ_ON (master, circuit->t_read, isis_receive, circuit,
+                  circuit->fd);
+#else
+  THREAD_TIMER_MSEC_ON (master, circuit->t_read, isis_receive, circuit,
+			listcount (circuit->area->circuit_list) * 100);
+#endif
+}
+
 int
 isis_circuit_up (struct isis_circuit *circuit)
 {
@@ -715,13 +727,7 @@ isis_circuit_up (struct isis_circuit *circuit)
   isis_circuit_stream(circuit, &circuit->rcv_stream);
   isis_circuit_stream(circuit, &circuit->snd_stream);
 
-#ifdef GNU_LINUX
-  THREAD_READ_ON (master, circuit->t_read, isis_receive, circuit,
-                  circuit->fd);
-#else
-  THREAD_TIMER_MSEC_ON (master, circuit->t_read, isis_receive, circuit,
-			listcount (circuit->area->circuit_list) * 100);
-#endif
+  isis_circuit_prepare (circuit);
 
   circuit->lsp_queue = list_new ();
   circuit->lsp_queue_last_cleared = time (NULL);
diff --git a/isisd/isis_circuit.h b/isisd/isis_circuit.h
index efe153f32e..035e558c0a 100644
--- a/isisd/isis_circuit.h
+++ b/isisd/isis_circuit.h
@@ -168,6 +168,7 @@ void isis_circuit_add_addr (struct isis_circuit *circuit,
 			    struct connected *conn);
 void isis_circuit_del_addr (struct isis_circuit *circuit,
 			    struct connected *conn);
+void isis_circuit_prepare (struct isis_circuit *circuit);
 int isis_circuit_up (struct isis_circuit *circuit);
 void isis_circuit_down (struct isis_circuit *);
 void circuit_update_nlpids (struct isis_circuit *circuit);
diff --git a/isisd/isis_pdu.c b/isisd/isis_pdu.c
index 6fec498a4d..96e459a797 100644
--- a/isisd/isis_pdu.c
+++ b/isisd/isis_pdu.c
@@ -2134,41 +2134,6 @@ isis_handle_pdu (struct isis_circuit *circuit, u_char * ssnpa)
   return retval;
 }
 
-#ifdef GNU_LINUX
-int
-isis_receive (struct thread *thread)
-{
-  struct isis_circuit *circuit;
-  u_char ssnpa[ETH_ALEN];
-  int retval;
-
-  /*
-   * Get the circuit 
-   */
-  circuit = THREAD_ARG (thread);
-  assert (circuit);
-
-  isis_circuit_stream(circuit, &circuit->rcv_stream);
-
-  retval = circuit->rx (circuit, ssnpa);
-  circuit->t_read = NULL;
-
-  if (retval == ISIS_OK)
-    retval = isis_handle_pdu (circuit, ssnpa);
-
-  /* 
-   * prepare for next packet. 
-   */
-  if (!circuit->is_passive)
-  {
-    THREAD_READ_ON (master, circuit->t_read, isis_receive, circuit,
-                    circuit->fd);
-  }
-
-  return retval;
-}
-
-#else
 int
 isis_receive (struct thread *thread)
 {
@@ -2195,18 +2160,11 @@ isis_receive (struct thread *thread)
    * prepare for next packet. 
    */
   if (!circuit->is_passive)
-  {
-    circuit->t_read = thread_add_timer_msec (master, isis_receive, circuit,
-  					     listcount
-					     (circuit->area->circuit_list) *
-					     100);
-  }
+    isis_circuit_prepare (circuit);
 
   return retval;
 }
 
-#endif
-
  /* filling of the fixed isis header */
 void
 fill_fixed_hdr (struct isis_fixed_hdr *hdr, u_char pdu_type)