diff --git a/rest-api/resources/src/main/java/org/eclipse/kapua/app/api/resources/v1/resources/DataMessages.java b/rest-api/resources/src/main/java/org/eclipse/kapua/app/api/resources/v1/resources/DataMessages.java
index 85e66421067..98b8039355b 100644
--- a/rest-api/resources/src/main/java/org/eclipse/kapua/app/api/resources/v1/resources/DataMessages.java
+++ b/rest-api/resources/src/main/java/org/eclipse/kapua/app/api/resources/v1/resources/DataMessages.java
@@ -91,15 +91,15 @@ public <V extends Comparable<V>> MessageListResult simpleQuery(@PathParam("scope
                                                                    @QueryParam("startDate") DateParam startDateParam,
                                                                    @QueryParam("endDate") DateParam endDateParam,
                                                                    @QueryParam("metricName") String metricName,
-                                                                   @QueryParam("metricType") MetricType<V> metricType,
+                                                                   @QueryParam("metricType") String metricType,
                                                                    @QueryParam("metricMin") String metricMinValue,
                                                                    @QueryParam("metricMax") String metricMaxValue,
                                                                    @QueryParam("sortDir") @DefaultValue("DESC") SortDirection sortDir,
                                                                    @QueryParam("offset") @DefaultValue("0") int offset,
                                                                    @QueryParam("limit") @DefaultValue("50") int limit)
             throws KapuaException {
-
-        MessageQuery query = parametersToQuery(datastorePredicateFactory, messageStoreFactory, scopeId, clientId, channel, strictChannel, startDateParam, endDateParam, metricName, metricType, metricMinValue, metricMaxValue, sortDir, offset, limit);
+        MetricType<V> internalMetricType = new MetricType<>(metricType);
+        MessageQuery query = parametersToQuery(datastorePredicateFactory, messageStoreFactory, scopeId, clientId, channel, strictChannel, startDateParam, endDateParam, metricName, internalMetricType, metricMinValue, metricMaxValue, sortDir, offset, limit);
 
         return query(scopeId, query);
     }
diff --git a/rest-api/resources/src/main/java/org/eclipse/kapua/app/api/resources/v1/resources/DataMessagesJson.java b/rest-api/resources/src/main/java/org/eclipse/kapua/app/api/resources/v1/resources/DataMessagesJson.java
index afa058ddafb..44fac949ad3 100644
--- a/rest-api/resources/src/main/java/org/eclipse/kapua/app/api/resources/v1/resources/DataMessagesJson.java
+++ b/rest-api/resources/src/main/java/org/eclipse/kapua/app/api/resources/v1/resources/DataMessagesJson.java
@@ -93,14 +93,15 @@ public <V extends Comparable<V>> JsonMessageListResult simpleQueryJson(@PathPara
                                                                            @QueryParam("startDate") DateParam startDateParam,
                                                                            @QueryParam("endDate") DateParam endDateParam,
                                                                            @QueryParam("metricName") String metricName,
-                                                                           @QueryParam("metricType") MetricType<V> metricType,
+                                                                           @QueryParam("metricType") String metricType,
                                                                            @QueryParam("metricMin") String metricMinValue,
                                                                            @QueryParam("metricMax") String metricMaxValue,
                                                                            @QueryParam("sortDir") @DefaultValue("DESC") SortDirection sortDir,
                                                                            @QueryParam("offset") @DefaultValue("0") int offset,
                                                                            @QueryParam("limit") @DefaultValue("50") int limit)
             throws KapuaException {
-        MessageQuery query = DataMessages.parametersToQuery(datastorePredicateFactory, messageStoreFactory, scopeId, clientId, channel, strictChannel, startDateParam, endDateParam, metricName, metricType, metricMinValue, metricMaxValue, sortDir, offset, limit);
+        MetricType<V> internalMetricType = new MetricType<>(metricType);
+        MessageQuery query = DataMessages.parametersToQuery(datastorePredicateFactory, messageStoreFactory, scopeId, clientId, channel, strictChannel, startDateParam, endDateParam, metricName, internalMetricType , metricMinValue, metricMaxValue, sortDir, offset, limit);
         query.setScopeId(scopeId);
         final MessageListResult result = messageStoreService.query(query);