diff --git a/src/pugixml.cpp b/src/pugixml.cpp
index 8ff879b..47764c8 100644
--- a/src/pugixml.cpp
+++ b/src/pugixml.cpp
@@ -4708,7 +4708,7 @@ PUGI__NS_BEGIN
 		xml_encoding buffer_encoding = impl::get_buffer_encoding(encoding, contents, size);
 
 		// if convert_buffer below throws bad_alloc, we still need to deallocate contents if we own it
-		auto_deleter<void> contents_guard(own ? contents : NULL, xml_memory::deallocate);
+		auto_deleter<void> contents_guard(own ? contents : 0, xml_memory::deallocate);
 
 		// get private buffer
 		char_t* buffer = 0;
@@ -4718,7 +4718,7 @@ PUGI__NS_BEGIN
 		if (!impl::convert_buffer(buffer, length, buffer_encoding, contents, size, is_mutable)) return impl::make_parse_result(status_out_of_memory);
 
 		// after this we either deallocate contents (below) or hold on to it via doc->buffer, so we don't need to guard it
-		contents_guard.data = NULL;
+		contents_guard.release();
 
 		// delete original buffer if we performed a conversion
 		if (own && buffer != contents && contents) impl::xml_memory::deallocate(contents);