diff --git a/server/core/httpresponse.cc b/server/core/httpresponse.cc
index 89a28b28b..414a6710e 100644
--- a/server/core/httpresponse.cc
+++ b/server/core/httpresponse.cc
@@ -39,8 +39,10 @@ HttpResponse::HttpResponse(const HttpResponse& response):
 
 HttpResponse& HttpResponse::operator=(const HttpResponse& response)
 {
+    json_t* body = m_body;
     m_body = json_incref(response.m_body);
     m_code = response.m_code;
+    json_decref(body);
     return *this;
 }
 
diff --git a/server/core/server.cc b/server/core/server.cc
index 479382671..74341ff9a 100644
--- a/server/core/server.cc
+++ b/server/core/server.cc
@@ -1427,7 +1427,7 @@ json_t* server_to_json(const SERVER* server, const char* host)
 
         for (int i = 0; server->slaves[i]; i++)
         {
-            json_array_append(slaves, json_integer(server->slaves[i]));
+            json_array_append_new(slaves, json_integer(server->slaves[i]));
         }
 
         json_object_set_new(rval, "slaves", slaves);
diff --git a/server/core/session.cc b/server/core/session.cc
index f30d02be3..b05e02ece 100644
--- a/server/core/session.cc
+++ b/server/core/session.cc
@@ -1017,7 +1017,7 @@ json_t* session_to_json(const MXS_SESSION *session, const char *host)
     svc += "/services/";
     svc += session->service->name;
 
-    json_array_append(arr, json_string(svc.c_str()));
+    json_array_append_new(arr, json_string(svc.c_str()));
     json_object_set_new(rel, "services", arr);
     json_object_set_new(rval, "relationships", rel);
 
diff --git a/server/core/users.cc b/server/core/users.cc
index 6a119c63d..a5e5db868 100644
--- a/server/core/users.cc
+++ b/server/core/users.cc
@@ -123,7 +123,7 @@ json_t* users_default_diagnostic(SERV_LISTENER *port)
 
             while ((user = (char*)hashtable_next(iter)))
             {
-                json_array_append(rval, json_string(user));
+                json_array_append_new(rval, json_string(user));
             }
 
             hashtable_iterator_free(iter);
diff --git a/server/modules/authenticator/MySQLAuth/mysql_auth.c b/server/modules/authenticator/MySQLAuth/mysql_auth.c
index c3ef0f964..2a79d3b50 100644
--- a/server/modules/authenticator/MySQLAuth/mysql_auth.c
+++ b/server/modules/authenticator/MySQLAuth/mysql_auth.c
@@ -687,7 +687,7 @@ int diag_cb(void *data, int columns, char **row, char **field_names)
     json_object_set_new(obj, "host", json_string(row[1]));
 
     json_t* arr = (json_t*)data;
-    json_array_append(arr, obj);
+    json_array_append_new(arr, obj);
     return 0;
 }
 
diff --git a/server/modules/filter/ccrfilter/ccrfilter.c b/server/modules/filter/ccrfilter/ccrfilter.c
index 6ea2e7853..51f3b2b58 100644
--- a/server/modules/filter/ccrfilter/ccrfilter.c
+++ b/server/modules/filter/ccrfilter/ccrfilter.c
@@ -363,22 +363,22 @@ static json_t* diagnostic(MXS_FILTER *instance, MXS_FILTER_SESSION *fsession)
     CCR_INSTANCE *my_instance = (CCR_INSTANCE *)instance;
     json_t* rval = json_object();
 
-    json_object_set(rval, "count", json_integer(my_instance->count));
-    json_object_set(rval, "time", json_integer(my_instance->time));
+    json_object_set_new(rval, "count", json_integer(my_instance->count));
+    json_object_set_new(rval, "time", json_integer(my_instance->time));
 
     if (my_instance->match)
     {
-        json_object_set(rval, "match", json_string(my_instance->match));
+        json_object_set_new(rval, "match", json_string(my_instance->match));
     }
 
     if (my_instance->nomatch)
     {
-        json_object_set(rval, "nomatch", json_string(my_instance->nomatch));
+        json_object_set_new(rval, "nomatch", json_string(my_instance->nomatch));
     }
 
-    json_object_set(rval, "data_modifications", json_integer(my_instance->stats.n_modified));
-    json_object_set(rval, "hints_added_count", json_integer(my_instance->stats.n_add_count));
-    json_object_set(rval, "hints_added_time", json_integer(my_instance->stats.n_add_time));
+    json_object_set_new(rval, "data_modifications", json_integer(my_instance->stats.n_modified));
+    json_object_set_new(rval, "hints_added_count", json_integer(my_instance->stats.n_add_count));
+    json_object_set_new(rval, "hints_added_time", json_integer(my_instance->stats.n_add_time));
 
     return rval;
 }
diff --git a/server/modules/filter/dbfwfilter/dbfwfilter.c b/server/modules/filter/dbfwfilter/dbfwfilter.c
index 6fd542d1c..22bb392e0 100644
--- a/server/modules/filter/dbfwfilter/dbfwfilter.c
+++ b/server/modules/filter/dbfwfilter/dbfwfilter.c
@@ -298,7 +298,7 @@ static json_t* rules_to_json(RULE *rules)
 
     for (RULE *rule = rules; rule; rule = rule->next)
     {
-        json_array_append(rval, rule_to_json(rule));
+        json_array_append_new(rval, rule_to_json(rule));
     }
 
     return rval;
diff --git a/server/modules/filter/namedserverfilter/namedserverfilter.cc b/server/modules/filter/namedserverfilter/namedserverfilter.cc
index a5a6891e2..4b16ec99a 100644
--- a/server/modules/filter/namedserverfilter/namedserverfilter.cc
+++ b/server/modules/filter/namedserverfilter/namedserverfilter.cc
@@ -347,7 +347,7 @@ json_t* RegexHintFilter::diagnostics()
 
             for (StringArray::iterator it2 = it->m_targets.begin(); it2 != it->m_targets.end(); it2++)
             {
-                json_array_append(targets, json_string(it2->c_str()));
+                json_array_append_new(targets, json_string(it2->c_str()));
             }
 
             json_object_set_new(obj, "match", json_string(it->m_match.c_str()));
diff --git a/server/modules/filter/topfilter/topfilter.c b/server/modules/filter/topfilter/topfilter.c
index 1876f1537..56b0ea5a4 100644
--- a/server/modules/filter/topfilter/topfilter.c
+++ b/server/modules/filter/topfilter/topfilter.c
@@ -621,7 +621,7 @@ static json_t* diagnostic(MXS_FILTER *instance, MXS_FILTER_SESSION *fsession)
                 json_object_set_new(obj, "time", json_real(exec_time));
                 json_object_set_new(obj, "sql", json_string(my_session->top[i]->sql));
 
-                json_array_append(arr, obj);
+                json_array_append_new(arr, obj);
             }
         }
 
diff --git a/server/modules/monitor/mysqlmon/mysql_mon.c b/server/modules/monitor/mysqlmon/mysql_mon.c
index 56e50c2a7..c961bc5b1 100644
--- a/server/modules/monitor/mysqlmon/mysql_mon.c
+++ b/server/modules/monitor/mysqlmon/mysql_mon.c
@@ -361,7 +361,7 @@ static json_t* diagnostics(const MXS_MONITOR *mon)
                 json_object_set_new(srv, "master_group", json_integer(serv_info->group));
             }
 
-            json_array_append(arr, srv);
+            json_array_append_new(arr, srv);
         }
 
         json_object_set_new(rval, "server_info", arr);
diff --git a/server/modules/routing/avrorouter/avro.c b/server/modules/routing/avrorouter/avro.c
index 9a401bbe1..2807eb90d 100644
--- a/server/modules/routing/avrorouter/avro.c
+++ b/server/modules/routing/avrorouter/avro.c
@@ -860,7 +860,7 @@ static json_t* diagnostics(MXS_ROUTER *router)
             snprintf(pathbuf, sizeof(pathbuf), "%lu-%lu-%lu", session->gtid.domain,
                      session->gtid.server_id, session->gtid.seq);
             json_object_set_new(client, "current_gtid", json_string(pathbuf));
-            json_array_append(arr, client);
+            json_array_append_new(arr, client);
         }
         spinlock_release(&router_inst->lock);
 
diff --git a/server/modules/routing/binlogrouter/blr.c b/server/modules/routing/binlogrouter/blr.c
index b83fae692..c83268c7a 100644
--- a/server/modules/routing/binlogrouter/blr.c
+++ b/server/modules/routing/binlogrouter/blr.c
@@ -1603,7 +1603,7 @@ static json_t* diagnostics(MXS_ROUTER *router)
 
             json_object_set_new(slave, "mode", json_string(mode));
 
-            json_array_append(arr, slave);
+            json_array_append_new(arr, slave);
         }
         spinlock_release(&router_inst->lock);
 
diff --git a/server/modules/routing/hintrouter/hintrouter.cc b/server/modules/routing/hintrouter/hintrouter.cc
index c699e162e..5e932de76 100644
--- a/server/modules/routing/hintrouter/hintrouter.cc
+++ b/server/modules/routing/hintrouter/hintrouter.cc
@@ -155,7 +155,7 @@ json_t* HintRouter::diagnostics()
     {
         if (default_action_values[i].enum_value == (uint64_t)m_default_action)
         {
-            json_array_append(arr, json_string(default_action_values[i].name));
+            json_array_append_new(arr, json_string(default_action_values[i].name));
         }
     }