diff --git a/ext/dom/attr.c b/ext/dom/attr.c
index 057d0d52e94..5929d88c7f2 100644
--- a/ext/dom/attr.c
+++ b/ext/dom/attr.c
@@ -92,6 +92,12 @@ int dom_attr_name_read(dom_object *obj, zval **retval TSRMLS_DC)
 	xmlAttrPtr attrp;
 
 	attrp = (xmlAttrPtr) dom_object_get_node(obj);
+
+	if (attrp == NULL) {
+		php_dom_throw_error(INVALID_STATE_ERR, 0 TSRMLS_CC);
+		return FAILURE;
+	}
+
 	ALLOC_ZVAL(*retval);
 	ZVAL_STRING(*retval, (char *) (attrp->name), 1);
 
@@ -131,6 +137,11 @@ int dom_attr_value_read(dom_object *obj, zval **retval TSRMLS_DC)
 
 	attrp = (xmlAttrPtr) dom_object_get_node(obj);
 
+	if (attrp == NULL) {
+		php_dom_throw_error(INVALID_STATE_ERR, 0 TSRMLS_CC);
+		return FAILURE;
+	}
+
 	ALLOC_ZVAL(*retval);
 
 	
@@ -152,6 +163,11 @@ int dom_attr_value_write(dom_object *obj, zval *newval TSRMLS_DC)
 
 	attrp = (xmlAttrPtr) dom_object_get_node(obj);
 
+	if (attrp == NULL) {
+		php_dom_throw_error(INVALID_STATE_ERR, 0 TSRMLS_CC);
+		return FAILURE;
+	}
+
 	if (attrp->children) {
 		node_list_unlink(attrp->children TSRMLS_CC);
 	}
@@ -190,6 +206,11 @@ int dom_attr_owner_element_read(dom_object *obj, zval **retval TSRMLS_DC)
 
 	nodep = dom_object_get_node(obj);
 
+	if (nodep == NULL) {
+		php_dom_throw_error(INVALID_STATE_ERR, 0 TSRMLS_CC);
+		return FAILURE;
+	}
+
 	nodeparent = nodep->parent;
 	if (!nodeparent) {
 		return FAILURE;
diff --git a/ext/dom/characterdata.c b/ext/dom/characterdata.c
index 65a5518bd05..d917ede44b0 100644
--- a/ext/dom/characterdata.c
+++ b/ext/dom/characterdata.c
@@ -56,6 +56,11 @@ int dom_characterdata_data_read(dom_object *obj, zval **retval TSRMLS_DC)
 
 	nodep = dom_object_get_node(obj);
 
+	if (nodep == NULL) {
+		php_dom_throw_error(INVALID_STATE_ERR, 0 TSRMLS_CC);
+		return FAILURE;
+	}
+
 	ALLOC_ZVAL(*retval);
 	
 	if ((content = xmlNodeGetContent(nodep)) != NULL) {
@@ -75,6 +80,11 @@ int dom_characterdata_data_write(dom_object *obj, zval *newval TSRMLS_DC)
 
 	nodep = dom_object_get_node(obj);
 
+	if (nodep == NULL) {
+		php_dom_throw_error(INVALID_STATE_ERR, 0 TSRMLS_CC);
+		return FAILURE;
+	}
+
 	if (newval->type != IS_STRING) {
 		if(newval->refcount > 1) {
 			value_copy = *newval;
@@ -108,6 +118,11 @@ int dom_characterdata_length_read(dom_object *obj, zval **retval TSRMLS_DC)
 
 	nodep = dom_object_get_node(obj);
 
+	if (nodep == NULL) {
+		php_dom_throw_error(INVALID_STATE_ERR, 0 TSRMLS_CC);
+		return FAILURE;
+	}
+
 	ALLOC_ZVAL(*retval);
 	
 	content = xmlNodeGetContent(nodep);
diff --git a/ext/dom/document.c b/ext/dom/document.c
index e6d84c8788c..c53b7bdb3c3 100644
--- a/ext/dom/document.c
+++ b/ext/dom/document.c
@@ -101,6 +101,11 @@ int dom_document_doctype_read(dom_object *obj, zval **retval TSRMLS_DC)
 
 	docp = (xmlDocPtr) dom_object_get_node(obj);
 
+	if (docp == NULL) {
+		php_dom_throw_error(INVALID_STATE_ERR, 0 TSRMLS_CC);
+		return FAILURE;
+	}
+
 	dtdptr = xmlGetIntSubset(docp);
 	if (!dtdptr) {
 		return FAILURE;
@@ -148,6 +153,11 @@ int dom_document_document_element_read(dom_object *obj, zval **retval TSRMLS_DC)
 
 	docp = (xmlDocPtr) dom_object_get_node(obj);
 
+	if (docp == NULL) {
+		php_dom_throw_error(INVALID_STATE_ERR, 0 TSRMLS_CC);
+		return FAILURE;
+	}
+
 	root = xmlDocGetRootElement(docp);
 	if (!root) {
 		return FAILURE;
@@ -195,6 +205,12 @@ int dom_document_encoding_read(dom_object *obj, zval **retval TSRMLS_DC)
 	char *encoding;
 
 	docp = (xmlDocPtr) dom_object_get_node(obj);
+
+	if (docp == NULL) {
+		php_dom_throw_error(INVALID_STATE_ERR, 0 TSRMLS_CC);
+		return FAILURE;
+	}
+
 	encoding = (char *) docp->encoding;
 	ALLOC_ZVAL(*retval);
 
@@ -215,6 +231,11 @@ int dom_document_encoding_write(dom_object *obj, zval *newval TSRMLS_DC)
 
 	docp = (xmlDocPtr) dom_object_get_node(obj);
 
+	if (docp == NULL) {
+		php_dom_throw_error(INVALID_STATE_ERR, 0 TSRMLS_CC);
+		return FAILURE;
+	}
+
 	if (newval->type != IS_STRING) {
 		if(newval->refcount > 1) {
 			value_copy = *newval;
@@ -258,6 +279,12 @@ int dom_document_standalone_read(dom_object *obj, zval **retval TSRMLS_DC)
 	int standalone;
 
 	docp = (xmlDocPtr) dom_object_get_node(obj);
+
+	if (docp == NULL) {
+		php_dom_throw_error(INVALID_STATE_ERR, 0 TSRMLS_CC);
+		return FAILURE;
+	}
+
 	ALLOC_ZVAL(*retval);
 	standalone = docp->standalone;
 	ZVAL_BOOL(*retval, standalone);
@@ -273,6 +300,11 @@ int dom_document_standalone_write(dom_object *obj, zval *newval TSRMLS_DC)
 
 	docp = (xmlDocPtr) dom_object_get_node(obj);
 
+	if (docp == NULL) {
+		php_dom_throw_error(INVALID_STATE_ERR, 0 TSRMLS_CC);
+		return FAILURE;
+	}
+
 	if(newval->refcount > 1) {
 		value_copy = *newval;
 		zval_copy_ctor(&value_copy);
@@ -313,6 +345,12 @@ int dom_document_version_read(dom_object *obj, zval **retval TSRMLS_DC)
 	char *version;
 
 	docp = (xmlDocPtr) dom_object_get_node(obj);
+
+	if (docp == NULL) {
+		php_dom_throw_error(INVALID_STATE_ERR, 0 TSRMLS_CC);
+		return FAILURE;
+	}
+
 	version = (char *) docp->version;
 	ALLOC_ZVAL(*retval);
 
@@ -331,6 +369,12 @@ int dom_document_version_write(dom_object *obj, zval *newval TSRMLS_DC)
 	xmlDoc *docp;
 
 	docp = (xmlDocPtr) dom_object_get_node(obj);
+
+	if (docp == NULL) {
+		php_dom_throw_error(INVALID_STATE_ERR, 0 TSRMLS_CC);
+		return FAILURE;
+	}
+
 	if (docp->version != NULL) {
 		xmlFree((xmlChar *) docp->version );
 	}
@@ -626,6 +670,11 @@ int dom_document_document_uri_read(dom_object *obj, zval **retval TSRMLS_DC)
 
 	docp = (xmlDocPtr) dom_object_get_node(obj);
 
+	if (docp == NULL) {
+		php_dom_throw_error(INVALID_STATE_ERR, 0 TSRMLS_CC);
+		return FAILURE;
+	}
+
 	ALLOC_ZVAL(*retval);
 	url = (char *) docp->URL;
 	if (url != NULL) {
@@ -643,6 +692,12 @@ int dom_document_document_uri_write(dom_object *obj, zval *newval TSRMLS_DC)
 	xmlDoc *docp;
 
 	docp = (xmlDocPtr) dom_object_get_node(obj);
+
+	if (docp == NULL) {
+		php_dom_throw_error(INVALID_STATE_ERR, 0 TSRMLS_CC);
+		return FAILURE;
+	}
+
 	if (docp->URL != NULL) {
 		xmlFree((xmlChar *) docp->URL);
 	}
@@ -1025,8 +1080,6 @@ PHP_FUNCTION(dom_document_create_element_ns)
 
 	DOM_GET_OBJ(docp, id, xmlDocPtr, intern);
 
-	DOM_GET_THIS_OBJ(docp, id, xmlDocPtr, intern);
-
 	errorcode = dom_check_qname(name, &localname, &prefix, uri_len, name_len);
 
 	if (errorcode == 0) {
diff --git a/ext/dom/documenttype.c b/ext/dom/documenttype.c
index 571b17e3d8b..2e0323e8105 100644
--- a/ext/dom/documenttype.c
+++ b/ext/dom/documenttype.c
@@ -50,6 +50,12 @@ int dom_documenttype_name_read(dom_object *obj, zval **retval TSRMLS_DC)
 	xmlDtdPtr dtdptr;
 
 	dtdptr = (xmlDtdPtr) dom_object_get_node(obj);
+
+	if (dtdptr == NULL) {
+		php_dom_throw_error(INVALID_STATE_ERR, 0 TSRMLS_CC);
+		return FAILURE;
+	}
+
 	ALLOC_ZVAL(*retval);
 	ZVAL_STRING(*retval, (char *) (dtdptr->name), 1);
 
@@ -73,6 +79,11 @@ int dom_documenttype_entities_read(dom_object *obj, zval **retval TSRMLS_DC)
 
 	doctypep = (xmlDtdPtr) dom_object_get_node(obj);
 
+	if (doctypep == NULL) {
+		php_dom_throw_error(INVALID_STATE_ERR, 0 TSRMLS_CC);
+		return FAILURE;
+	}
+
 	MAKE_STD_ZVAL(*retval);
 	php_dom_create_interator(*retval, DOM_NAMEDNODEMAP TSRMLS_CC);
 
@@ -101,6 +112,11 @@ int dom_documenttype_notations_read(dom_object *obj, zval **retval TSRMLS_DC)
 
 	doctypep = (xmlDtdPtr) dom_object_get_node(obj);
 
+	if (doctypep == NULL) {
+		php_dom_throw_error(INVALID_STATE_ERR, 0 TSRMLS_CC);
+		return FAILURE;
+	}
+
 	MAKE_STD_ZVAL(*retval);
 	php_dom_create_interator(*retval, DOM_NAMEDNODEMAP TSRMLS_CC);
 
@@ -127,6 +143,11 @@ int dom_documenttype_public_id_read(dom_object *obj, zval **retval TSRMLS_DC)
 
 	dtdptr = (xmlDtdPtr) dom_object_get_node(obj);
 
+	if (dtdptr == NULL) {
+		php_dom_throw_error(INVALID_STATE_ERR, 0 TSRMLS_CC);
+		return FAILURE;
+	}
+
 	ALLOC_ZVAL(*retval);
 	if (dtdptr->ExternalID) {
 		ZVAL_STRING(*retval, (char *) (dtdptr->ExternalID), 1);
@@ -152,6 +173,11 @@ int dom_documenttype_system_id_read(dom_object *obj, zval **retval TSRMLS_DC)
 
 	dtdptr = (xmlDtdPtr) dom_object_get_node(obj);
 
+	if (dtdptr == NULL) {
+		php_dom_throw_error(INVALID_STATE_ERR, 0 TSRMLS_CC);
+		return FAILURE;
+	}
+
 	ALLOC_ZVAL(*retval);
 	if (dtdptr->SystemID) {
 		ZVAL_STRING(*retval, (char *) (dtdptr->SystemID), 1);
@@ -180,6 +206,11 @@ int dom_documenttype_internal_subset_read(dom_object *obj, zval **retval TSRMLS_
 
 	dtdptr = (xmlDtdPtr) dom_object_get_node(obj);
 
+	if (dtdptr == NULL) {
+		php_dom_throw_error(INVALID_STATE_ERR, 0 TSRMLS_CC);
+		return FAILURE;
+	}
+
 	ALLOC_ZVAL(*retval);
 
 	if (dtdptr->doc != NULL && ((intsubset = dtdptr->doc->intSubset) != NULL)) {
diff --git a/ext/dom/element.c b/ext/dom/element.c
index 3c6bfa183b0..ac5cd0311dd 100644
--- a/ext/dom/element.c
+++ b/ext/dom/element.c
@@ -109,6 +109,12 @@ int dom_element_tag_name_read(dom_object *obj, zval **retval TSRMLS_DC)
 	xmlChar *qname;
 
 	nodep = dom_object_get_node(obj);
+
+	if (nodep == NULL) {
+		php_dom_throw_error(INVALID_STATE_ERR, 0 TSRMLS_CC);
+		return FAILURE;
+	}
+
 	ALLOC_ZVAL(*retval);
 	ns = nodep->ns;
 	if (ns != NULL && ns->prefix) {
diff --git a/ext/dom/entity.c b/ext/dom/entity.c
index c8327808cd5..9e7420dac47 100644
--- a/ext/dom/entity.c
+++ b/ext/dom/entity.c
@@ -52,6 +52,11 @@ int dom_entity_public_id_read(dom_object *obj, zval **retval TSRMLS_DC)
 
 	nodep = (xmlEntity *) dom_object_get_node(obj);
 
+	if (nodep == NULL) {
+		php_dom_throw_error(INVALID_STATE_ERR, 0 TSRMLS_CC);
+		return FAILURE;
+	}
+
 	ALLOC_ZVAL(*retval);
 	if (nodep->etype != XML_EXTERNAL_GENERAL_UNPARSED_ENTITY) {
 		ZVAL_NULL(*retval);
@@ -77,6 +82,11 @@ int dom_entity_system_id_read(dom_object *obj, zval **retval TSRMLS_DC)
 
 	nodep = (xmlEntity *) dom_object_get_node(obj);
 
+	if (nodep == NULL) {
+		php_dom_throw_error(INVALID_STATE_ERR, 0 TSRMLS_CC);
+		return FAILURE;
+	}
+
 	ALLOC_ZVAL(*retval);
 	if (nodep->etype != XML_EXTERNAL_GENERAL_UNPARSED_ENTITY) {
 		ZVAL_NULL(*retval);
@@ -103,6 +113,11 @@ int dom_entity_notation_name_read(dom_object *obj, zval **retval TSRMLS_DC)
 
 	nodep = (xmlEntity *) dom_object_get_node(obj);
 
+	if (nodep == NULL) {
+		php_dom_throw_error(INVALID_STATE_ERR, 0 TSRMLS_CC);
+		return FAILURE;
+	}
+
 	ALLOC_ZVAL(*retval);
 	if (nodep->etype != XML_EXTERNAL_GENERAL_UNPARSED_ENTITY) {
 		ZVAL_NULL(*retval);
diff --git a/ext/dom/node.c b/ext/dom/node.c
index b0aa096d1b6..d6843364fae 100644
--- a/ext/dom/node.c
+++ b/ext/dom/node.c
@@ -86,6 +86,11 @@ int dom_node_node_name_read(dom_object *obj, zval **retval TSRMLS_DC)
 
 	nodep = dom_object_get_node(obj);
 
+	if (nodep == NULL) {
+		php_dom_throw_error(INVALID_STATE_ERR, 0 TSRMLS_CC);
+		return FAILURE;
+	}
+
 	switch (nodep->type) {
 		case XML_ATTRIBUTE_NODE:
 		case XML_ELEMENT_NODE:
@@ -170,6 +175,12 @@ int dom_node_node_value_read(dom_object *obj, zval **retval TSRMLS_DC)
 	char *str = NULL;
 
 	nodep = dom_object_get_node(obj);
+
+	if (nodep == NULL) {
+		php_dom_throw_error(INVALID_STATE_ERR, 0 TSRMLS_CC);
+		return FAILURE;
+	}
+
 	/* Access to Element node is implemented as a convience method */
 	switch (nodep->type) {
 		case XML_ATTRIBUTE_NODE:
@@ -209,6 +220,11 @@ int dom_node_node_value_write(dom_object *obj, zval *newval TSRMLS_DC)
 
 	nodep = dom_object_get_node(obj);
 
+	if (nodep == NULL) {
+		php_dom_throw_error(INVALID_STATE_ERR, 0 TSRMLS_CC);
+		return FAILURE;
+	}
+
 	/* Access to Element node is implemented as a convience method */
 	switch (nodep->type) {
 		case XML_ELEMENT_NODE:
@@ -255,6 +271,11 @@ int dom_node_node_type_read(dom_object *obj, zval **retval TSRMLS_DC)
 
 	nodep = dom_object_get_node(obj);
 
+	if (nodep == NULL) {
+		php_dom_throw_error(INVALID_STATE_ERR, 0 TSRMLS_CC);
+		return FAILURE;
+	}
+
 	ALLOC_ZVAL(*retval);
 
 	/* Specs dictate that they are both type XML_DOCUMENT_TYPE_NODE */
@@ -283,6 +304,11 @@ int dom_node_parent_node_read(dom_object *obj, zval **retval TSRMLS_DC)
 
 	nodep = dom_object_get_node(obj);
 
+	if (nodep == NULL) {
+		php_dom_throw_error(INVALID_STATE_ERR, 0 TSRMLS_CC);
+		return FAILURE;
+	}
+
 	nodeparent = nodep->parent;
 	if (!nodeparent) {
 		return FAILURE;
@@ -313,6 +339,11 @@ int dom_node_child_nodes_read(dom_object *obj, zval **retval TSRMLS_DC)
 
 	nodep = dom_object_get_node(obj);
 
+	if (nodep == NULL) {
+		php_dom_throw_error(INVALID_STATE_ERR, 0 TSRMLS_CC);
+		return FAILURE;
+	}
+
 	ALLOC_ZVAL(*retval);
 	
 	if (dom_node_children_valid(nodep) == FAILURE) {
@@ -342,6 +373,11 @@ int dom_node_first_child_read(dom_object *obj, zval **retval TSRMLS_DC)
 
 	nodep = dom_object_get_node(obj);
 
+	if (nodep == NULL) {
+		php_dom_throw_error(INVALID_STATE_ERR, 0 TSRMLS_CC);
+		return FAILURE;
+	}
+
 	if (dom_node_children_valid(nodep) == SUCCESS) {
 		first = nodep->children;
 	}
@@ -375,6 +411,11 @@ int dom_node_last_child_read(dom_object *obj, zval **retval TSRMLS_DC)
 
 	nodep = dom_object_get_node(obj);
 
+	if (nodep == NULL) {
+		php_dom_throw_error(INVALID_STATE_ERR, 0 TSRMLS_CC);
+		return FAILURE;
+	}
+
 	if (dom_node_children_valid(nodep) == SUCCESS) {
 		last = nodep->last;
 	}
@@ -408,6 +449,11 @@ int dom_node_previous_sibling_read(dom_object *obj, zval **retval TSRMLS_DC)
 
 	nodep = dom_object_get_node(obj);
 
+	if (nodep == NULL) {
+		php_dom_throw_error(INVALID_STATE_ERR, 0 TSRMLS_CC);
+		return FAILURE;
+	}
+
 	prevsib = nodep->prev;
 	if (!prevsib) {
 		return FAILURE;
@@ -438,6 +484,11 @@ int dom_node_next_sibling_read(dom_object *obj, zval **retval TSRMLS_DC)
 
 	nodep = dom_object_get_node(obj);
 
+	if (nodep == NULL) {
+		php_dom_throw_error(INVALID_STATE_ERR, 0 TSRMLS_CC);
+		return FAILURE;
+	}
+
 	nextsib = nodep->next;
 	if (!nextsib) {
 		return FAILURE;
@@ -468,6 +519,11 @@ int dom_node_attributes_read(dom_object *obj, zval **retval TSRMLS_DC)
 
 	nodep = dom_object_get_node(obj);
 
+	if (nodep == NULL) {
+		php_dom_throw_error(INVALID_STATE_ERR, 0 TSRMLS_CC);
+		return FAILURE;
+	}
+
 	ALLOC_ZVAL(*retval);
 
 	if (nodep->type == XML_ELEMENT_NODE) {
@@ -498,6 +554,11 @@ int dom_node_owner_document_read(dom_object *obj, zval **retval TSRMLS_DC)
 
 	nodep = dom_object_get_node(obj);
 
+	if (nodep == NULL) {
+		php_dom_throw_error(INVALID_STATE_ERR, 0 TSRMLS_CC);
+		return FAILURE;
+	}
+
 	if (nodep->type == XML_DOCUMENT_NODE || nodep->type == XML_HTML_DOCUMENT_NODE) {
 		ALLOC_ZVAL(*retval);
 		ZVAL_NULL(*retval);
@@ -534,6 +595,11 @@ int dom_node_namespace_uri_read(dom_object *obj, zval **retval TSRMLS_DC)
 
 	nodep = dom_object_get_node(obj);
 
+	if (nodep == NULL) {
+		php_dom_throw_error(INVALID_STATE_ERR, 0 TSRMLS_CC);
+		return FAILURE;
+	}
+
 	switch (nodep->type) {
 		case XML_ELEMENT_NODE:
 		case XML_ATTRIBUTE_NODE:
@@ -575,6 +641,11 @@ int dom_node_prefix_read(dom_object *obj, zval **retval TSRMLS_DC)
 
 	nodep = dom_object_get_node(obj);
 
+	if (nodep == NULL) {
+		php_dom_throw_error(INVALID_STATE_ERR, 0 TSRMLS_CC);
+		return FAILURE;
+	}
+
 	switch (nodep->type) {
 		case XML_ELEMENT_NODE:
 		case XML_ATTRIBUTE_NODE:
@@ -611,6 +682,11 @@ int dom_node_prefix_write(dom_object *obj, zval *newval TSRMLS_DC)
 
 	nodep = dom_object_get_node(obj);
 
+	if (nodep == NULL) {
+		php_dom_throw_error(INVALID_STATE_ERR, 0 TSRMLS_CC);
+		return FAILURE;
+	}
+
 	switch (nodep->type) {
 		case XML_ELEMENT_NODE:
 		case XML_ATTRIBUTE_NODE:
@@ -682,6 +758,11 @@ int dom_node_local_name_read(dom_object *obj, zval **retval TSRMLS_DC)
 
 	nodep = dom_object_get_node(obj);
 
+	if (nodep == NULL) {
+		php_dom_throw_error(INVALID_STATE_ERR, 0 TSRMLS_CC);
+		return FAILURE;
+	}
+
 	ALLOC_ZVAL(*retval);
 
 	if (nodep->type == XML_ELEMENT_NODE || nodep->type == XML_ATTRIBUTE_NODE || nodep->type == XML_NAMESPACE_DECL) {
@@ -709,6 +790,11 @@ int dom_node_base_uri_read(dom_object *obj, zval **retval TSRMLS_DC)
 
 	nodep = dom_object_get_node(obj);
 
+	if (nodep == NULL) {
+		php_dom_throw_error(INVALID_STATE_ERR, 0 TSRMLS_CC);
+		return FAILURE;
+	}
+
 	ALLOC_ZVAL(*retval);
 
 	baseuri = xmlNodeGetBase(nodep->doc, nodep);
@@ -738,6 +824,11 @@ int dom_node_text_content_read(dom_object *obj, zval **retval TSRMLS_DC)
 
 	nodep = dom_object_get_node(obj);
 
+	if (nodep == NULL) {
+		php_dom_throw_error(INVALID_STATE_ERR, 0 TSRMLS_CC);
+		return FAILURE;
+	}
+
 	str = xmlNodeGetContent(nodep);
 
 	ALLOC_ZVAL(*retval);
diff --git a/ext/dom/notation.c b/ext/dom/notation.c
index 01e8f6db954..f43d6ae12cf 100644
--- a/ext/dom/notation.c
+++ b/ext/dom/notation.c
@@ -51,6 +51,12 @@ int dom_notation_public_id_read(dom_object *obj, zval **retval TSRMLS_DC)
 	xmlNotationPtr nodep;
 
 	nodep = (xmlNotationPtr) dom_object_get_node(obj);
+
+	if (nodep == NULL) {
+		php_dom_throw_error(INVALID_STATE_ERR, 0 TSRMLS_CC);
+		return FAILURE;
+	}
+
 	ALLOC_ZVAL(*retval);
 	if (nodep->PublicID) {
 		ZVAL_STRING(*retval, (char *) (nodep->PublicID), 1);
@@ -75,6 +81,12 @@ int dom_notation_system_id_read(dom_object *obj, zval **retval TSRMLS_DC)
 	xmlNotationPtr nodep;
 
 	nodep = (xmlNotationPtr) dom_object_get_node(obj);
+
+	if (nodep == NULL) {
+		php_dom_throw_error(INVALID_STATE_ERR, 0 TSRMLS_CC);
+		return FAILURE;
+	}
+
 	ALLOC_ZVAL(*retval);
 	if (nodep->SystemID) {
 		ZVAL_STRING(*retval, (char *) (nodep->PublicID), 1);
diff --git a/ext/dom/processinginstruction.c b/ext/dom/processinginstruction.c
index c73d2d23ae3..b17e11bc9b2 100644
--- a/ext/dom/processinginstruction.c
+++ b/ext/dom/processinginstruction.c
@@ -86,6 +86,11 @@ int dom_processinginstruction_target_read(dom_object *obj, zval **retval TSRMLS_
 
 	nodep = dom_object_get_node(obj);
 
+	if (nodep == NULL) {
+		php_dom_throw_error(INVALID_STATE_ERR, 0 TSRMLS_CC);
+		return FAILURE;
+	}
+
 	ALLOC_ZVAL(*retval);
 	ZVAL_STRING(*retval, (char *) (nodep->name), 1);
 
@@ -108,6 +113,11 @@ int dom_processinginstruction_data_read(dom_object *obj, zval **retval TSRMLS_DC
 
 	nodep = dom_object_get_node(obj);
 
+	if (nodep == NULL) {
+		php_dom_throw_error(INVALID_STATE_ERR, 0 TSRMLS_CC);
+		return FAILURE;
+	}
+
 	ALLOC_ZVAL(*retval);
 
 	
@@ -128,6 +138,11 @@ int dom_processinginstruction_data_write(dom_object *obj, zval *newval TSRMLS_DC
 
 	nodep = dom_object_get_node(obj);
 
+	if (nodep == NULL) {
+		php_dom_throw_error(INVALID_STATE_ERR, 0 TSRMLS_CC);
+		return FAILURE;
+	}
+
 	if (newval->type != IS_STRING) {
 		if(newval->refcount > 1) {
 			value_copy = *newval;
diff --git a/ext/dom/text.c b/ext/dom/text.c
index 05fca65ded7..85230c89c61 100644
--- a/ext/dom/text.c
+++ b/ext/dom/text.c
@@ -85,6 +85,11 @@ int dom_text_whole_text_read(dom_object *obj, zval **retval TSRMLS_DC)
 
 	node = dom_object_get_node(obj);
 
+	if (node == NULL) {
+		php_dom_throw_error(INVALID_STATE_ERR, 0 TSRMLS_CC);
+		return FAILURE;
+	}
+
 	ALLOC_ZVAL(*retval);
 	wholetext = xmlNodeListGetString(node->doc, node, 1);
 	ZVAL_STRING(*retval, wholetext, 1);