diff --git a/src/main/lemondronor/advisorycircular.cljs b/src/main/lemondronor/advisorycircular.cljs
index 794471f..16b302e 100644
--- a/src/main/lemondronor/advisorycircular.cljs
+++ b/src/main/lemondronor/advisorycircular.cljs
@@ -6,7 +6,6 @@
    [cljs.reader :as reader]
    [clojure.set :as set]
    [clojure.string :as string]
-   [fipp.edn :as fippedn]
    [kitchen-async.promise :as p]
    [lemondronor.advisorycircular.adsbx :as adsbx]
    [lemondronor.advisorycircular.generation :as generation]
@@ -157,7 +156,7 @@
 
 
 (defn write-history-db [db path]
-  (fs/writeFileSync path (with-out-str (fippedn/pprint db)))
+  (fs/writeFileSync path (.stringify js/JSON (clj->js db) nil "  "))
   db)
 
 
@@ -165,8 +164,8 @@
 ;; resolves to the database value.
 
 (defn read-history-db [path]
-  (p/let [edn-str (util/read-file path {:encoding "utf-8"})
-          db (reader/read-string edn-str)]
+  (p/let [json-str (util/read-file path {:encoding "utf-8"})
+          db (js->clj (.parse js/JSON json-str))]
     (log-verbose "Loaded %s aircraft from database %s" (count db) path)
     db))
 
@@ -265,11 +264,6 @@
       v)))
 
 
-(defn debug-prn [x msg]
-  (println msg (with-out-str (fippedn/pprint x)))
-  x)
-
-
 (defn closest-airport [config lat lon]
   (p/let [results (pelias/nearby (:pelias config)
                                  lat lon
@@ -566,7 +560,7 @@
    ;; close to an airport, then it's probably just doing flight
    ;; training.
    :minimum-airport-distance-km 2.5
-   :history-db-path "advisorycircular.edn"
+   :history-db-path "advisorycircular.json"
    :basestation-sqb "basestation.sqb"
    :twitter {:enabled? true}})
 
@@ -634,7 +628,7 @@
       (.option "--no-tweeting" "Do not tweet")
       (.option "--config <path>" "Path to the configuration yaml file")
       (.option "--secrets <path>" "Path to the secrets yaml file" "secrets.yaml")
-      (.option "--history <path>" "Path to history/state file" "advisorycircular.edn")
+      (.option "--history <path>" "Path to history/state file" "advisorycircular.json")
       (.option "--log-prefix <prefix>" "Log prefix to use")
       (.parse (.-argv js/process)))
   (logging/set-log-prefix! (or (.-logPrefix commander) ""))