diff --git a/Backend/tools-services/src/main/java/com/r11/tools/controller/XPathController.java b/Backend/tools-services/src/main/java/com/r11/tools/controller/XPathController.java
index 635fbe9..62fae00 100644
--- a/Backend/tools-services/src/main/java/com/r11/tools/controller/XPathController.java
+++ b/Backend/tools-services/src/main/java/com/r11/tools/controller/XPathController.java
@@ -28,7 +28,7 @@ public class XPathController implements RestController {
     }
 
     private XMLResponseBody prepareErrorResponse(String message, String processor) {
-        return new XMLResponseBody(message, "ERR", processor, "N/A");
+        return new XMLResponseBody(message, "ERR", processor, -1);
     }
 
     @ScopedControllerManifest(method = HandlerType.POST, path = "/xpath")
@@ -71,7 +71,7 @@ public class XPathController implements RestController {
             response.status(200);
             long duration = System.currentTimeMillis() - timeStart;
             responseBody = new XMLResponseBody(xPathQueryResult.getData().trim(),
-                    "OK", xalan.getVersion(), String.valueOf(duration));
+                    "OK", xalan.getVersion(),duration);
             
             responseBody.setType(xPathQueryResult.getType());
             this.logger.info("Request (XPath, Xalan) processed in " + duration + " ms.");
@@ -98,7 +98,7 @@ public class XPathController implements RestController {
 
             long duration = System.currentTimeMillis() - timeStart;
             String processor = "Saxon " + saxon.getVersion() + " " + requestBody.getVersion() + " over s9api";
-            responseBody = new XMLResponseBody(result, "OK", processor, String.valueOf(duration));
+            responseBody = new XMLResponseBody(result, "OK", processor, duration);
 
             this.logger.info("Request (XPath, Saxon) processed in " + duration + " ms.");
         } catch (Exception ex) {
diff --git a/Backend/tools-services/src/main/java/com/r11/tools/model/XMLResponseBody.java b/Backend/tools-services/src/main/java/com/r11/tools/model/XMLResponseBody.java
index dbcca48..42e52c1 100644
--- a/Backend/tools-services/src/main/java/com/r11/tools/model/XMLResponseBody.java
+++ b/Backend/tools-services/src/main/java/com/r11/tools/model/XMLResponseBody.java
@@ -5,12 +5,12 @@ public class XMLResponseBody {
     private String result;
     private String status;
     private String processor;
-    private String duration;
+    private long duration;
 
     // Optional
     private String type;
 
-    public XMLResponseBody(String result, String status, String processor, String duration) {
+    public XMLResponseBody(String result, String status, String processor, long duration) {
         this.result = result;
         this.status = status;
         this.processor = processor;
@@ -41,11 +41,11 @@ public class XMLResponseBody {
         this.processor = processor;
     }
 
-    public String getDuration() {
+    public long getDuration() {
         return duration;
     }
 
-    public void setDuration(String duration) {
+    public void setDuration(long duration) {
         this.duration = duration;
     }