diff --git a/lib/extras.py b/lib/extras.py
index ac784b8e..c3babf47 100644
--- a/lib/extras.py
+++ b/lib/extras.py
@@ -488,16 +488,15 @@ import select
 from psycopg2.extensions import POLL_OK, POLL_READ, POLL_WRITE
 from psycopg2 import OperationalError
 
-def wait_select(conn, curs=None):
+def wait_select(conn):
     """Wait until a connection or cursor has data available.
 
     The function is an example of a wait callback to be registered with
     `~psycopg2.extensions.set_wait_callback()`. This function uses `!select()`
     to wait for data available.
     """
-    poll = (curs or conn).poll
     while 1:
-        state = poll()
+        state = conn.poll()
         if state == POLL_OK:
             break
         elif state == POLL_READ:
diff --git a/psycopg/connection_int.c b/psycopg/connection_int.c
index b0074b10..d87f9ca8 100644
--- a/psycopg/connection_int.c
+++ b/psycopg/connection_int.c
@@ -366,7 +366,7 @@ conn_sync_connect(connectionObject *self)
 
     /* if the connection is green, wait to finish connection */
     if (green) {
-        wait_rv = psyco_wait((PyObject *)self, Py_None);
+        wait_rv = psyco_wait(self);
         if (wait_rv) {
             Py_DECREF(wait_rv);
         } else {
diff --git a/psycopg/green.c b/psycopg/green.c
index 5fe0bebb..fc9605db 100644
--- a/psycopg/green.c
+++ b/psycopg/green.c
@@ -115,7 +115,7 @@ have_wait_callback()
  * The function returns the return value of the called function.
  */
 PyObject *
-psyco_wait(PyObject *conn, PyObject *curs)
+psyco_wait(connectionObject *conn)
 {
     PyObject *rv;
     PyObject *cb;
@@ -125,7 +125,7 @@ psyco_wait(PyObject *conn, PyObject *curs)
         return NULL;
     }
 
-    rv = PyObject_CallFunctionObjArgs(cb, conn, curs, NULL);
+    rv = PyObject_CallFunctionObjArgs(cb, conn, NULL);
     Py_DECREF(cb);
 
     return rv;
@@ -160,7 +160,7 @@ psyco_exec_green(connectionObject *conn, const char *command)
     /* Ensure the query reached the server. */
     conn->async_status = ASYNC_WRITE;
 
-    pyrv = PyObject_CallFunctionObjArgs(cb, conn, NULL, NULL);
+    pyrv = PyObject_CallFunctionObjArgs(cb, conn, NULL);
     if (!pyrv) {
         Dprintf("psyco_exec_green: error in callback sending query");
         goto clear;
@@ -170,7 +170,7 @@ psyco_exec_green(connectionObject *conn, const char *command)
     /* Loop reading data using the user-provided wait function */
     conn->async_status = ASYNC_READ;
 
-    pyrv = PyObject_CallFunctionObjArgs(cb, conn, NULL, NULL);
+    pyrv = PyObject_CallFunctionObjArgs(cb, conn, NULL);
     if (!pyrv) {
         Dprintf("psyco_exec_green: error in callback reading result");
         goto clear;
diff --git a/psycopg/green.h b/psycopg/green.h
index a21a9a17..16e83046 100644
--- a/psycopg/green.h
+++ b/psycopg/green.h
@@ -36,7 +36,7 @@ extern "C" {
 #define psyco_set_wait_callback_doc \
 "set_wait_callback(f) -- Register a callback function to block waiting for data.\n" \
 "\n" \
-"The callback must should signature :samp:`fun({conn}, {cur}=None)` and\n" \
+"The callback should have signature :samp:`fun({conn})` and\n" \
 "is called to wait for data available whenever a blocking function from the\n" \
 "libpq is called.  Use `!register_wait_function(None)` to revert to the\n" \
 "original behaviour (using blocking libpq functions).\n" \
@@ -56,7 +56,7 @@ HIDDEN PyObject *psyco_set_wait_callback(PyObject *self, PyObject *obj);
 HIDDEN PyObject *psyco_get_wait_callback(PyObject *self, PyObject *obj);
 
 HIDDEN int psyco_green(void);
-HIDDEN PyObject *psyco_wait(PyObject *conn, PyObject *curs);
+HIDDEN PyObject *psyco_wait(connectionObject *conn);
 HIDDEN PGresult *psyco_exec_green(connectionObject *conn, const char *command);
 
 #ifdef __cplusplus