diff --git a/src/taxodb_rrna.py b/src/taxodb_rrna.py
index c25ae16..6965fae 100644
--- a/src/taxodb_rrna.py
+++ b/src/taxodb_rrna.py
@@ -203,7 +203,7 @@ def extract_gg(input=None, bdb=None, sep='||'):
                                  metavar="<db type>",
                                  type=str,
                                  required=True,
-                                 choices=['silva' 'greengenes'])
+                                 choices=['silva', 'greengenes'])
 
     args = parser.parse_args()
 
@@ -216,6 +216,7 @@ def extract_gg(input=None, bdb=None, sep='||'):
             extract_gg(input=args.fasta, bdb=bdb)
     except IOError as err:
         print >> sys.stderr, "Can't open input file %s: %s" % (args.fasta, str(err))
+        sys.exit(1)
     except db.DBAccessError as err:
         print >> sys.stderr, "Error while opening Berkeley database %s: %s" % (args.accVos_oc, str(err))
         sys.exit(1)