diff --git a/psycopg/connection_int.c b/psycopg/connection_int.c
index 34c695747443cf47d3f0e9e4e28ac947b0f974d2..8365e048b9a99118f0b4dff932673df93a2ad11f 100644
--- a/psycopg/connection_int.c
+++ b/psycopg/connection_int.c
@@ -33,6 +33,7 @@
 #include "psycopg/green.h"
 #include "psycopg/notify.h"
 
+#include <stdlib.h>
 #include <string.h>
 
 /* String indexes match the ISOLATION_LEVEL_* consts */
diff --git a/psycopg/connection_type.c b/psycopg/connection_type.c
index 1672c999a153ed76f2a4af20f3c72e5b7925c0d0..077654e56a6e3836f0e8ef622fcdce8589038a2b 100644
--- a/psycopg/connection_type.c
+++ b/psycopg/connection_type.c
@@ -35,6 +35,7 @@
 #include "psycopg/green.h"
 #include "psycopg/xid.h"
 
+#include <stdlib.h>
 #include <string.h>
 #include <ctype.h>
 #include "psycopg/typecast.h"
diff --git a/psycopg/pqpath.c b/psycopg/pqpath.c
index 7ab56cbe6b5400a61253476f7d89f5fc09fd181d..03802d6e6de491a3ea3aa6b409e0b8eabe89f7bd 100644
--- a/psycopg/pqpath.c
+++ b/psycopg/pqpath.c
@@ -47,6 +47,7 @@
 #include "psycopg/libpq_support.h"
 #include "libpq-fe.h"
 
+#include <stdlib.h>
 #ifdef _WIN32
 /* select() */
 #include <winsock2.h>
diff --git a/psycopg/psycopgmodule.c b/psycopg/psycopgmodule.c
index 5ab6f5fdd156b1add3aa9b698bb5ca2da39495ef..d129e87a000bae5c9f8ff747788f3115b78f0b29 100644
--- a/psycopg/psycopgmodule.c
+++ b/psycopg/psycopgmodule.c
@@ -57,6 +57,8 @@
 #include <datetime.h>
 #include "psycopg/adapter_datetime.h"
 
+#include <stdlib.h>
+
 HIDDEN PyObject *psycoEncodings = NULL;
 HIDDEN PyObject *sqlstate_errors = NULL;
 
@@ -999,32 +1001,35 @@ INIT_MODULE(_psycopg)(void)
 
     /* initialize types and objects not exposed to the module */
     Py_SET_TYPE(&typecastType, &PyType_Type);
-    if (0 > PyType_Ready(&typecastType)) { goto exit; }
+    if (0 > PyType_Ready(&typecastType)) { goto error; }
 
     Py_SET_TYPE(&chunkType, &PyType_Type);
-    if (0 > PyType_Ready(&chunkType)) { goto exit; }
+    if (0 > PyType_Ready(&chunkType)) { goto error; }
 
     Py_SET_TYPE(&errorType, &PyType_Type);
     errorType.tp_base = (PyTypeObject *)PyExc_StandardError;
-    if (0 > PyType_Ready(&errorType)) { goto exit; }
+    if (0 > PyType_Ready(&errorType)) { goto error; }
 
-    if (!(psyco_null = Bytes_FromString("NULL"))) { goto exit; }
+    if (!(psyco_null = Bytes_FromString("NULL"))) { goto error; }
 
     /* initialize the module */
     module = PyModule_Create(&psycopgmodule);
-    if (!module) { goto exit; }
+    if (!module) { goto error; }
 
-    if (0 > add_module_constants(module)) { goto exit; }
-    if (0 > add_module_types(module)) { goto exit; }
-    if (0 > datetime_init()) { goto exit; }
-    if (0 > encodings_init(module)) { goto exit; }
-    if (0 > typecast_init(module)) { goto exit; }
-    if (0 > adapters_init(module)) { goto exit; }
-    if (0 > basic_errors_init(module)) { goto exit; }
-    if (0 > sqlstate_errors_init(module)) { goto exit; }
+    if (0 > add_module_constants(module)) { goto error; }
+    if (0 > add_module_types(module)) { goto error; }
+    if (0 > datetime_init()) { goto error; }
+    if (0 > encodings_init(module)) { goto error; }
+    if (0 > typecast_init(module)) { goto error; }
+    if (0 > adapters_init(module)) { goto error; }
+    if (0 > basic_errors_init(module)) { goto error; }
+    if (0 > sqlstate_errors_init(module)) { goto error; }
 
     Dprintf("psycopgmodule: module initialization complete");
 
-exit:
     return module;
+error:
+    if (module)
+        Py_DECREF(module);
+    return NULL;
 }
diff --git a/psycopg/replication_connection_type.c b/psycopg/replication_connection_type.c
index b8c1d2debd8e45c270c70dbfd882263c17cb09e9..7e51904781f29bd4ba049a229be2a92b0e6c613c 100644
--- a/psycopg/replication_connection_type.c
+++ b/psycopg/replication_connection_type.c
@@ -129,6 +129,11 @@ replicationConnection_repr(replicationConnectionObject *self)
         self, self->conn.dsn, self->conn.closed);
 }
 
+static int
+replicationConnectionType_traverse(PyObject *self, visitproc visit, void *arg)
+{
+    return connectionType.tp_traverse(self, visit, arg);
+}
 
 /* object calculated member list */
 
@@ -173,7 +178,7 @@ PyTypeObject replicationConnectionType = {
     Py_TPFLAGS_DEFAULT | Py_TPFLAGS_BASETYPE | Py_TPFLAGS_HAVE_ITER |
       Py_TPFLAGS_HAVE_GC, /*tp_flags*/
     replicationConnectionType_doc, /*tp_doc*/
-    0,          /*tp_traverse*/
+    replicationConnectionType_traverse, /*tp_traverse*/
     0,          /*tp_clear*/
     0,          /*tp_richcompare*/
     0,          /*tp_weaklistoffset*/
diff --git a/psycopg/replication_cursor_type.c b/psycopg/replication_cursor_type.c
index 689a131cf05a5707ddac0fae6078b9d84571fa92..ab3ad3c4e403de61d76dd6c25166a9180b57a6d7 100644
--- a/psycopg/replication_cursor_type.c
+++ b/psycopg/replication_cursor_type.c
@@ -346,6 +346,11 @@ replicationCursor_repr(replicationCursorObject *self)
         "<ReplicationCursor object at %p; closed: %d>", self, self->cur.closed);
 }
 
+static int
+replicationCursorType_traverse(PyObject *self, visitproc visit, void *arg)
+{
+    return cursorType.tp_traverse(self, visit, arg);
+}
 
 /* object type */
 
@@ -374,7 +379,7 @@ PyTypeObject replicationCursorType = {
     Py_TPFLAGS_DEFAULT | Py_TPFLAGS_BASETYPE | Py_TPFLAGS_HAVE_ITER |
       Py_TPFLAGS_HAVE_GC, /*tp_flags*/
     replicationCursorType_doc, /*tp_doc*/
-    0,          /*tp_traverse*/
+    replicationCursorType_traverse, /*tp_traverse*/
     0,          /*tp_clear*/
     0,          /*tp_richcompare*/
     0,          /*tp_weaklistoffset*/