diff --git a/src/lib/util/cdrom.cpp b/src/lib/util/cdrom.cpp
index aa82ae438f1..159a9c964a1 100644
--- a/src/lib/util/cdrom.cpp
+++ b/src/lib/util/cdrom.cpp
@@ -865,7 +865,8 @@ std::error_condition cdrom_file::parse_metadata(chd_file *chd, toc &toc)
 	std::string metadata;
 	std::error_condition err;
 
-	toc.flags = 0;
+	/* clear structures */
+	memset(&toc, 0, sizeof(toc));
 
 	/* start with no tracks */
 	for (toc.numtrks = 0; toc.numtrks < MAX_TRACKS; toc.numtrks++)