diff --git a/set-search-api-client/src/main/java/eu/europeana/set/search/service/impl/SearchApiClientImpl.java b/set-search-api-client/src/main/java/eu/europeana/set/search/service/impl/SearchApiClientImpl.java
index b74379e5..8a8df077 100644
--- a/set-search-api-client/src/main/java/eu/europeana/set/search/service/impl/SearchApiClientImpl.java
+++ b/set-search-api-client/src/main/java/eu/europeana/set/search/service/impl/SearchApiClientImpl.java
@@ -171,9 +171,9 @@ public JSONObject searchItems(String uri, String postBody) throws SearchApiClien
     CloseableHttpResponse jsonResponse;
     try {
       if (postBody != null) {
-        jsonResponse = createHttpConnection().post(uri, postBody, null, null);
+        jsonResponse = createHttpConnection().post(uri, postBody, "application/json", null);
       } else {
-        jsonResponse = createHttpConnection().get(uri, null, null);
+        jsonResponse = createHttpConnection().get(uri, "application/json", null);
       }
       if (jsonResponse == null) {
         // HTTP Error Code