diff --git a/src/main/java/eu/dnetlib/repo/manager/service/RepositoryServiceImpl.java b/src/main/java/eu/dnetlib/repo/manager/service/RepositoryServiceImpl.java
index 898bbb1..ed8f062 100644
--- a/src/main/java/eu/dnetlib/repo/manager/service/RepositoryServiceImpl.java
+++ b/src/main/java/eu/dnetlib/repo/manager/service/RepositoryServiceImpl.java
@@ -287,16 +287,14 @@ public class RepositoryServiceImpl implements RepositoryService {
         requestFilter.setEnglishname(englishName);
 
         try {
-            String rs = restTemplate.postForObject(uriComponents.toUri(), requestFilter, String.class);
+            Map rs = restTemplate.postForObject(uriComponents.toUri(), requestFilter, Map.class);
             if (rs == null) {
                 logger.error("DSM response is null : [url={}]", uriComponents.toUri());
             } else {
-                JSONObject response = new JSONObject(rs);
-                JSONArray jsonArray = (JSONArray) response.get("datasourceInfo");
-                Header header = mapper.readValue(response.get("header").toString(), Header.class);
+                Header header = mapper.readValue(mapper.writeValueAsString(rs.get("header")), Header.class);
                 snippets = Paging.of(header,
                         mapper.readValue(
-                                String.valueOf(jsonArray),
+                                mapper.writeValueAsString(rs.get("datasourceInfo")),
                                 mapper.getTypeFactory().constructCollectionType(List.class, RepositorySnippet.class)));
             }