diff --git a/java_tools/proxy_server/src/main/java/com/rusefi/server/Backend.java b/java_tools/proxy_server/src/main/java/com/rusefi/server/Backend.java
index 64cf5ae798..a3bbb6e65a 100644
--- a/java_tools/proxy_server/src/main/java/com/rusefi/server/Backend.java
+++ b/java_tools/proxy_server/src/main/java/com/rusefi/server/Backend.java
@@ -178,7 +178,8 @@ public class Backend implements Closeable {
     }
 
     private void close(ApplicationConnectionState applicationConnectionState) {
-        applicationConnectionState.close();
+        if (applicationConnectionState != null)
+            applicationConnectionState.close();
         onDisconnectApplication(applicationConnectionState);
     }