diff --git a/api/src/main/java/be/naaturel/boardmateapi/controllers/ChatController.java b/api/src/main/java/be/naaturel/boardmateapi/controllers/ChatController.java
index f18ba839..b9503da6 100644
--- a/api/src/main/java/be/naaturel/boardmateapi/controllers/ChatController.java
+++ b/api/src/main/java/be/naaturel/boardmateapi/controllers/ChatController.java
@@ -17,9 +17,7 @@ import org.springframework.http.HttpStatus;
 import org.springframework.http.ResponseEntity;
 import org.springframework.web.bind.annotation.*;
 
-import java.util.HashSet;
 import java.util.List;
-import java.util.Set;
 import java.util.concurrent.ConcurrentHashMap;
 
 @RestController
@@ -28,7 +26,7 @@ public class ChatController {
     private final MessageService messageService;
     private final WebexService webexService;
     private final MqttService mqttService;
-    private final Set<String> expectedMessages;
+    private final ConcurrentHashMap<String, Integer> expectedMessages;
 
     @Autowired
     public ChatController(
@@ -38,7 +36,7 @@ public class ChatController {
         this.messageService = messageService;
         this.webexService = webexService;
         this.mqttService = mqttService;
-        this.expectedMessages = ConcurrentHashMap.newKeySet();
+        this.expectedMessages = new ConcurrentHashMap<>();
     }
 
     @PostMapping("/message/send")
@@ -55,7 +53,7 @@ public class ChatController {
             String messageId = this.webexService.post(model);
             model.setId(messageId);
             this.messageService.save(model);
-            expectedMessages.add(messageId);
+            expectedMessages.put(messageId, 0);
 
             result.setSuccess(true);
             result.setData(messageId);
@@ -112,13 +110,13 @@ public class ChatController {
             ObjectMapper mapper = new ObjectMapper();
             WebexWebhook payload = mapper.readValue(rawPayload, WebexWebhook.class);
 
-            boolean accepted = expectedMessages.remove(payload.getData().getId());
-            if (accepted) {
-                Logger.displayInfo("Accepted");
-            } else {
+            int seen = expectedMessages.get(payload.getData().getId());
+            if (seen == 2) {
                 Logger.displayInfo("Rejected");
+                expectedMessages.remove(payload.getData().getId());
                 return ResponseEntity.status(HttpStatus.UNAUTHORIZED).body(result);
             }
+            Logger.displayInfo("Accepted");
 
             Room room = webexService.getRoomById(payload.getData().getRoomId());
             Message msg = webexService.fetchMessage(payload.getData().getId());