diff --git a/bin/x509/ip-ssl-subject.py b/bin/x509/ip-ssl-subject.py
index 8bb0d19..2c35a91 100644
--- a/bin/x509/ip-ssl-subject.py
+++ b/bin/x509/ip-ssl-subject.py
@@ -12,12 +12,14 @@ import argparse
 import redis
 import sys
 import netaddr
+import json
 
 argParser = argparse.ArgumentParser(description='Tool to lookup IP for known fingerprints and X.509 subjects')
 argParser.add_argument('-b', default='127.0.0.1', help='Redis host (default is 127.0.0.1)')
 argParser.add_argument('-p', default=6379, help='Redis TCP port (default is 6379)')
 argParser.add_argument('-s', action='append', help='IPv4 subnet to lookup')
 argParser.add_argument('-v', action='store_true', help='Verbose output')
+argParser.add_argument('-o', default='readable', help='readable (default), json')
 args = argParser.parse_args()
 
 if args.s is None:
@@ -28,18 +30,38 @@ try:
     r = redis.StrictRedis(host=args.b, port=args.p)
 except:
     print "Unable to connect to the Redis server"
-    sys.exit(1)
+    sys.exit(255)
+
+if args.o == 'json':
+    out = {}
+elif args.o == 'readable':
+    pass
+else:
+    print "Unknown output format"
+    sys.exit(255)
 
 for subnet in args.s:
     iplist = netaddr.IPNetwork(subnet)
     for ip in iplist:
         s = r.smembers(ip)
         if s:
-            print ip
-            for x in s:
-                subjects = r.smembers(x)
+            if args.o == 'readable':
+                print ip
+            else:
+                out[str(ip)] = []
+            for fingerprint in s:
+                subjects = r.smembers(fingerprint)
                 if subjects:
                     for subject in subjects:
-                        print " " + subject
+                        if args.o == 'readable':
+                            print " " + subject
+                        else:
+                            out[str(ip)].append(subject)
                 else:
-                    print " " + x
+                    if args.o == 'readable':
+                        print " " + fingerprint
+                    else:
+                        out[str(ip)].append(fingerprint)
+
+if args.o == 'json':
+    print json.dumps(out)