diff --git a/lib/event/EventsAdapter.js b/lib/event/EventsAdapter.js
index aea02e7..fd3e53b 100644
--- a/lib/event/EventsAdapter.js
+++ b/lib/event/EventsAdapter.js
@@ -262,7 +262,13 @@ var EventsAdapter = function EventsAdapter() {
     //console.log('get events from ' + url);
 
     fetch(url)
-      .then((response) => response.json())
+      .then((response) => {
+        if (response.headers.get('content-type') === 'application/json') {
+          return response.json();
+        }
+
+        throw new TypeError();
+      })
       .catch((error) => {
         console.error(error);
         return callback(error, []);
diff --git a/lib/festival/FestivalsAdapter.js b/lib/festival/FestivalsAdapter.js
index 5c1236d..5f36b28 100644
--- a/lib/festival/FestivalsAdapter.js
+++ b/lib/festival/FestivalsAdapter.js
@@ -205,7 +205,13 @@ var FestivalsAdapter = function FestivalsAdapter() {
 
   var fetchFestivals = function fetchFestivals(callback) {
     fetch(API_URL + FESTIVALS_RESOURCE_NAME + FESTIVALS_QUERY)
-      .then((response) => response.json())
+      .then((response) => {
+        if (response.headers.get('content-type') === 'application/json') {
+          return response.json();
+        }
+
+        throw new TypeError();
+      })
       .catch((error) => {
         console.error(error);
         return callback(error, []);