diff --git a/src/main/java/eu/openaire/urls_controller/controllers/StatsController.java b/src/main/java/eu/openaire/urls_controller/controllers/StatsController.java
index ce733e7..07201be 100644
--- a/src/main/java/eu/openaire/urls_controller/controllers/StatsController.java
+++ b/src/main/java/eu/openaire/urls_controller/controllers/StatsController.java
@@ -6,6 +6,7 @@ import eu.openaire.urls_controller.services.StatsService;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.http.MediaType;
 import org.springframework.http.ResponseEntity;
 import org.springframework.web.bind.annotation.GetMapping;
 import org.springframework.web.bind.annotation.RequestMapping;
@@ -30,7 +31,7 @@ public class StatsController {
      * This endpoint returns the total number of payloads existing in the database, independently of the way they were aggregated.
      * This includes the payloads created by other pieces of software, before the PDF-Aggregation-Service was created.
      * */
-    @GetMapping("getNumberOfAllPayloads")
+    @GetMapping(value = "getNumberOfAllPayloads", produces = MediaType.TEXT_PLAIN_VALUE)
     public ResponseEntity<?> getNumberOfAllPayloads(boolean isCalledFromScheduler)
     {
         if ( ! isCalledFromScheduler )
@@ -44,7 +45,7 @@ public class StatsController {
     /**
      * This endpoint returns the number of payloads aggregated by the PDF-Aggregated-Service itself, through crawling.
      * */
-    @GetMapping("getNumberOfPayloadsAggregatedByServiceThroughCrawling")
+    @GetMapping(value = "getNumberOfPayloadsAggregatedByServiceThroughCrawling", produces = MediaType.TEXT_PLAIN_VALUE)
     public ResponseEntity<?> getNumberOfPayloadsAggregatedByServiceThroughCrawling(boolean isCalledFromScheduler)
     {
         if ( ! isCalledFromScheduler )
@@ -58,7 +59,7 @@ public class StatsController {
     /**
      * This endpoint returns the number of payloads aggregated by this Service, through BulkImport procedures with compatible datasources..
      * */
-    @GetMapping("getNumberOfPayloadsAggregatedByServiceThroughBulkImport")
+    @GetMapping(value = "getNumberOfPayloadsAggregatedByServiceThroughBulkImport", produces = MediaType.TEXT_PLAIN_VALUE)
     public ResponseEntity<?> getNumberOfPayloadsAggregatedByServiceThroughBulkImport(boolean isCalledFromScheduler)
     {
         if ( ! isCalledFromScheduler )
@@ -72,7 +73,7 @@ public class StatsController {
     /**
      * This endpoint returns the number of payloads aggregated by the PDF-Aggregated-Service itself, through crawling AND bulk-import procedures.
      * */
-    @GetMapping("getNumberOfPayloadsAggregatedByService")
+    @GetMapping(value = "getNumberOfPayloadsAggregatedByService", produces = MediaType.TEXT_PLAIN_VALUE)
     public ResponseEntity<?> getNumberOfPayloadsAggregatedByService(boolean isCalledFromScheduler)
     {
         if ( ! isCalledFromScheduler )
@@ -90,7 +91,7 @@ public class StatsController {
     /**
      * This endpoint returns the number of legacy payloads, which were aggregated by methods other thant the PDF Aggregation Service.
      * */
-    @GetMapping("getNumberOfLegacyPayloads")
+    @GetMapping(value = "getNumberOfLegacyPayloads", produces = MediaType.TEXT_PLAIN_VALUE)
     public ResponseEntity<?> getNumberOfLegacyPayloads(boolean isCalledFromScheduler)
     {
         if ( ! isCalledFromScheduler )
@@ -104,7 +105,7 @@ public class StatsController {
     /**
      * This endpoint returns the number of payloads related to the given datasourceID.
      * */
-    @GetMapping("getNumberOfPayloadsForDatasource")
+    @GetMapping(value = "getNumberOfPayloadsForDatasource", produces = MediaType.TEXT_PLAIN_VALUE)
     public ResponseEntity<?> getNumberOfPayloadsForDatasource(@RequestParam String datasourceId) {
         logger.info("Received a \"getNumberOfPayloadsForDatasource\" request.");
         final String getNumOfPayloadsForDatasourceQuery =
@@ -148,7 +149,7 @@ public class StatsController {
     /**
      * This endpoint returns the total number of distinct full-text files existing in the database.
      * */
-    @GetMapping("getNumberOfAllDistinctFullTexts")
+    @GetMapping(value = "getNumberOfAllDistinctFullTexts", produces = MediaType.TEXT_PLAIN_VALUE)
     public ResponseEntity<?> getNumberOfAllDistinctFullTexts() {
         logger.info("Received a \"getNumberOfAllDistinctFullTexts\" request.");
         final String getPayloadsNumberQuery = "select count(distinct `hash`) from " + ImpalaConnector.databaseName + ".payload";
@@ -159,7 +160,7 @@ public class StatsController {
     /**
      * This endpoint returns the number of records inspected by the PDF-Aggregation-Service, through crawling.
      * */
-    @GetMapping("getNumberOfRecordsInspectedByServiceThroughCrawling")
+    @GetMapping(value = "getNumberOfRecordsInspectedByServiceThroughCrawling", produces = MediaType.TEXT_PLAIN_VALUE)
     public ResponseEntity<?> getNumberOfRecordsInspectedByServiceThroughCrawling(boolean isCalledFromScheduler)
     {
         if ( ! isCalledFromScheduler )
diff --git a/src/main/java/eu/openaire/urls_controller/services/StatsServiceImpl.java b/src/main/java/eu/openaire/urls_controller/services/StatsServiceImpl.java
index df62f1d..1ab1a6e 100644
--- a/src/main/java/eu/openaire/urls_controller/services/StatsServiceImpl.java
+++ b/src/main/java/eu/openaire/urls_controller/services/StatsServiceImpl.java
@@ -37,7 +37,7 @@ public class StatsServiceImpl implements StatsService {
             if ( result != null ) {
                 int numOfPayloads = (int) result;
                 logger.info("The number of " + message + " in the database \"" + ImpalaConnector.databaseName + "\" is " + numOfPayloads);
-                return new ResponseEntity<>(numOfPayloads, HttpStatus.OK);
+                return ResponseEntity.ok(Integer.toString(numOfPayloads));
             } else
                 return ResponseEntity.status(HttpStatus.INTERNAL_SERVER_ERROR).body("The number of " + message + " could not be retrieved from the database \"" + ImpalaConnector.databaseName + "\" using the getNumberQuery: " + getNumberQuery);
         } catch (EmptyResultDataAccessException erdae) {
@@ -76,7 +76,7 @@ public class StatsServiceImpl implements StatsService {
             if ( result != null ) {
                 int numOfInspectedRecords = (int) result;
                 logger.info("Number of crawling-inspected records from the database \"" + ImpalaConnector.databaseName + "\" is " + numOfInspectedRecords);
-                return new ResponseEntity<>(numOfInspectedRecords, HttpStatus.OK);
+                return ResponseEntity.ok(Integer.toString(numOfInspectedRecords));
             } else
                 return ResponseEntity.status(HttpStatus.INTERNAL_SERVER_ERROR).body("The inspected records' number could not be retrieved from the database \"" + ImpalaConnector.databaseName + "\" using the getInspectedRecordsNumberQuery: " + getInspectedRecordsNumberQuery);
         } catch (EmptyResultDataAccessException erdae) {