diff --git a/app/javascript/dashboard/store/modules/conversations/index.js b/app/javascript/dashboard/store/modules/conversations/index.js
index 84be116fe..d7137694e 100644
--- a/app/javascript/dashboard/store/modules/conversations/index.js
+++ b/app/javascript/dashboard/store/modules/conversations/index.js
@@ -228,7 +228,10 @@ export const mutations = {
   },
 
   [types.ADD_CONVERSATION](_state, conversation) {
-    _state.allConversations.push(conversation);
+    const exists = _state.allConversations.some(c => c.id === conversation.id);
+    if (!exists) {
+      _state.allConversations.push(conversation);
+    }
   },
 
   [types.DELETE_CONVERSATION](_state, conversationId) {
diff --git a/app/javascript/dashboard/store/modules/specs/conversations/mutations.spec.js b/app/javascript/dashboard/store/modules/specs/conversations/mutations.spec.js
index 01abf05f7..bd048dbba 100644
--- a/app/javascript/dashboard/store/modules/specs/conversations/mutations.spec.js
+++ b/app/javascript/dashboard/store/modules/specs/conversations/mutations.spec.js
@@ -975,6 +975,16 @@ describe('#mutations', () => {
       mutations[types.ADD_CONVERSATION](state, conversation);
       expect(state.allConversations).toEqual([conversation]);
     });
+
+    it('should not add a duplicate conversation', () => {
+      const conversation = { id: 1, messages: [] };
+      const state = {
+        allConversations: [conversation],
+      };
+
+      mutations[types.ADD_CONVERSATION](state, { id: 1, messages: [] });
+      expect(state.allConversations).toHaveLength(1);
+    });
   });
 
   describe('#DELETE_CONVERSATION', () => {