diff --git a/bson/_cbsonmodule.c b/bson/_cbsonmodule.c
index 331e115ef4..b706c35e30 100644
--- a/bson/_cbsonmodule.c
+++ b/bson/_cbsonmodule.c
@@ -207,7 +207,7 @@ static PyObject* _test_long_long_to_str(PyObject* self, PyObject* args) {
  *
  * Returns a new ref */
 static PyObject* _error(char* name) {
-    PyObject* error;
+    PyObject* error = NULL;
     PyObject* errors = PyImport_ImportModule("bson.errors");
     if (!errors) {
         return NULL;
@@ -294,7 +294,7 @@ static PyObject* datetime_from_millis(long long millis) {
                                           timeinfo.tm_sec,
                                           microseconds);
     if(!datetime) {
-        PyObject *etype, *evalue, *etrace;
+        PyObject *etype = NULL, *evalue = NULL, *etrace = NULL;
 
         /*
         * Calling _error clears the error state, so fetch it first.
@@ -350,8 +350,8 @@ static PyObject* datetime_ms_from_millis(PyObject* self, long long millis){
         return NULL;
     }
 
-    PyObject* dt;
-    PyObject* ll_millis;
+    PyObject* dt = NULL;
+    PyObject* ll_millis = NULL;
 
     if (!(ll_millis = PyLong_FromLongLong(millis))){
         return NULL;
diff --git a/pymongo/_cmessagemodule.c b/pymongo/_cmessagemodule.c
index 43549baa0e..9c8fb550f2 100644
--- a/pymongo/_cmessagemodule.c
+++ b/pymongo/_cmessagemodule.c
@@ -31,7 +31,7 @@ struct module_state {
     PyObject* _max_bson_size_str;
     PyObject* _max_message_size_str;
     PyObject* _max_write_batch_size_str;
-    PyObject* _max_split_size_str;
+    PyObject* _max_split_size_str; 
 };
 
 /* See comments about module initialization in _cbsonmodule.c */
@@ -45,7 +45,7 @@ struct module_state {
  *
  * Returns a new ref */
 static PyObject* _error(char* name) {
-    PyObject* error;
+    PyObject* error = NULL;
     PyObject* errors = PyImport_ImportModule("pymongo.errors");
     if (!errors) {
         return NULL;
@@ -75,9 +75,9 @@ static PyObject* _cbson_query_message(PyObject* self, PyObject* args) {
     int begin, cur_size, max_size = 0;
     int num_to_skip;
     int num_to_return;
-    PyObject* query;
-    PyObject* field_selector;
-    PyObject* options_obj;
+    PyObject* query = NULL;
+    PyObject* field_selector = NULL;
+    PyObject* options_obj = NULL;
     codec_options_t options;
     buffer_t buffer = NULL;
     int length_location, message_length;
@@ -221,12 +221,12 @@ static PyObject* _cbson_op_msg(PyObject* self, PyObject* args) {
     /* NOTE just using a random number as the request_id */
     int request_id = rand();
     unsigned int flags;
-    PyObject* command;
+    PyObject* command = NULL;
     char* identifier = NULL;
     Py_ssize_t identifier_length = 0;
-    PyObject* docs;
-    PyObject* doc;
-    PyObject* options_obj;
+    PyObject* docs = NULL;
+    PyObject* doc = NULL;
+    PyObject* options_obj = NULL;
     codec_options_t options;
     buffer_t buffer = NULL;
     int length_location, message_length;
@@ -535,8 +535,8 @@ static PyObject*
 _cbson_encode_batched_op_msg(PyObject* self, PyObject* args) {
     unsigned char op;
     unsigned char ack;
-    PyObject* command;
-    PyObject* docs;
+    PyObject* command = NULL;
+    PyObject* docs = NULL;
     PyObject* ctx = NULL;
     PyObject* to_publish = NULL;
     PyObject* result = NULL;
@@ -592,8 +592,8 @@ _cbson_batched_op_msg(PyObject* self, PyObject* args) {
     unsigned char ack;
     int request_id;
     int position;
-    PyObject* command;
-    PyObject* docs;
+    PyObject* command = NULL;
+    PyObject* docs = NULL;
     PyObject* ctx = NULL;
     PyObject* to_publish = NULL;
     PyObject* result = NULL;
@@ -868,8 +868,8 @@ _cbson_encode_batched_write_command(PyObject* self, PyObject* args) {
     char *ns = NULL;
     unsigned char op;
     Py_ssize_t ns_len;
-    PyObject* command;
-    PyObject* docs;
+    PyObject* command = NULL;
+    PyObject* docs = NULL;
     PyObject* ctx = NULL;
     PyObject* to_publish = NULL;
     PyObject* result = NULL;