diff --git a/biostools/extractors.py b/biostools/extractors.py
index 7c2901e..5864417 100644
--- a/biostools/extractors.py
+++ b/biostools/extractors.py
@@ -1465,7 +1465,7 @@ class ISOExtractor(ArchiveExtractor):
 
 	def extract(self, file_path, file_header, dest_dir, dest_dir_0):
 		# Stop if this is not an ISO.
-		if file_header[32769:32774] != b'CD001' or file_header[32777:32782] != b'CDROM':
+		if file_header[32769:32774] != b'CD001' and file_header[32777:32782] != b'CDROM':
 			return False
 
 		# Extract this as an archive.