diff --git a/src/Psalm/CallMap.php b/src/Psalm/CallMap.php
index 6add7d563..f94e29447 100644
--- a/src/Psalm/CallMap.php
+++ b/src/Psalm/CallMap.php
@@ -1476,7 +1476,7 @@ return [
 'DOMImplementation::createDocument' => ['DOMDocument', 'namespaceuri='=>'string', 'qualifiedname='=>'string', 'doctype='=>'DOMDocumentType'],
 'DOMImplementation::createDocumentType' => ['DOMDocumentType', 'qualifiedname='=>'string', 'publicid='=>'string', 'systemid='=>'string'],
 'DOMImplementation::hasFeature' => ['bool', 'feature'=>'string', 'version'=>'string'],
-'dom_import_simplexml' => ['DOMElement', 'node'=>'SimpleXMLElement'],
+'dom_import_simplexml' => ['DOMElement|false', 'node'=>'SimpleXMLElement'],
 'DOMNamedNodeMap::getNamedItem' => ['DOMNode', 'name'=>'string'],
 'DOMNamedNodeMap::getNamedItemNS' => ['DOMNode', 'namespaceuri'=>'string', 'localname'=>'string'],
 'DOMNamedNodeMap::item' => ['DOMNode', 'index'=>'int'],
@@ -8075,7 +8075,7 @@ return [
 'SimpleXMLElement::registerXPathNamespace' => ['bool', 'prefix'=>'string', 'ns'=>'string'],
 'SimpleXMLElement::__toString' => ['string'],
 'SimpleXMLElement::xpath' => ['array', 'path'=>'string'],
-'simplexml_import_dom' => ['SimpleXMLElement', 'node'=>'DOMNode', 'class_name='=>'string'],
+'simplexml_import_dom' => ['SimpleXMLElement|false', 'node'=>'DOMNode', 'class_name='=>'string'],
 'SimpleXMLIterator::current' => ['SimpleXMLIterator'],
 'SimpleXMLIterator::getChildren' => ['SimpleXMLIterator'],
 'SimpleXMLIterator::hasChildren' => ['bool'],