diff --git a/src/src/main/java/com/my/graphiteDigesterBg/diframe/DiCommandRequest.java b/src/src/main/java/com/my/graphiteDigesterBg/diframe/DiCommandRequest.java
index dcb4bf4..de49308 100644
--- a/src/src/main/java/com/my/graphiteDigesterBg/diframe/DiCommandRequest.java
+++ b/src/src/main/java/com/my/graphiteDigesterBg/diframe/DiCommandRequest.java
@@ -27,7 +27,7 @@ public class DiCommandRequest {
     }
 
     // refresh id
-    public void refreshId() {
+    synchronized public void refreshId() {
         this.id = (short)idCounter++;
         if ( idCounter > 30000 ) {
             idCounter = 0;