diff --git a/scripts/autojson.py b/scripts/autojson.py
index 1a499df..4a5fc5c 100755
--- a/scripts/autojson.py
+++ b/scripts/autojson.py
@@ -27,5 +27,13 @@
     else:
         j["Exposes"] = sorted(j["Exposes"], key=lambda k: k["Type"])
 
+    nl = [s['Name'] for s in j['Exposes']]
+    ns = set(nl)
+    for n in ns:
+        t = nl.count(n)
+        if t != 1:
+            print('\033[1;35mthe %s appears %d times\033[0m!'%(n, t))
+            os._exit(-1)
+
     with open(file, 'w') as f:
         f.write(json.dumps(j, indent=4, sort_keys=True, separators=(',', ': ')))