diff --git a/injector b/injector
index 4b37d15..dd74043 100755
--- a/injector
+++ b/injector
@@ -24,6 +24,9 @@ args = parser.parse_args()
 
 f = open(args.hostsfile, 'r')
 for line in f:
+	if line.find('=') == -1:
+		print 'Invalid line: %s' % line
+		continue
 	entry = line.split('=')
 	try:
 		hostname = validate_hostname(entry[0])