diff --git a/stores/suggestion_store.jsx b/stores/suggestion_store.jsx
index 6646f1b4764d..9c752e68a6d8 100644
--- a/stores/suggestion_store.jsx
+++ b/stores/suggestion_store.jsx
@@ -117,6 +117,10 @@ class SuggestionStore extends EventEmitter {
         suggestion.selection = '';
     }
 
+    suggestionBoxExists(id) {
+        return this.suggestions.has(id);
+    }
+
     hasSuggestions(id) {
         return this.getSuggestions(id).terms.length > 0;
     }
@@ -250,6 +254,10 @@ class SuggestionStore extends EventEmitter {
     handleEventPayload(payload) {
         const {type, id, ...other} = payload.action;
 
+        if (id && !this.suggestionBoxExists(id)) {
+            return;
+        }
+
         switch (type) {
         case ActionTypes.SUGGESTION_PRETEXT_CHANGED:
             // Clear the suggestions if the pretext is empty or ends with whitespace
diff --git a/tests/stores/suggestion_store.test.jsx b/tests/stores/suggestion_store.test.jsx
new file mode 100644
index 000000000000..8d48fd80715b
--- /dev/null
+++ b/tests/stores/suggestion_store.test.jsx
@@ -0,0 +1,52 @@
+// Copyright (c) 2015-present Mattermost, Inc. All Rights Reserved.
+// See License.txt for license information.
+
+import assert from 'assert';
+
+import {ActionTypes} from 'utils/constants.jsx';
+import SuggestionStore from 'stores/suggestion_store.jsx';
+
+describe('stores/SuggestionStore', () => {
+    test('should ignore events from unknown suggestion boxes', () => {
+        const id = 'unknown';
+        const pretext = 'pretext';
+        SuggestionStore.handleEventPayload({
+            action: {
+                id,
+                type: ActionTypes.SUGGESTION_PRETEXT_CHANGED,
+                pretext,
+            },
+        });
+        assert.equal(SuggestionStore.suggestions.has(id), false);
+    });
+
+    test('should process events from registered suggestion boxes', () => {
+        const id = 'id1';
+        const pretext = 'pretext';
+        SuggestionStore.registerSuggestionBox(id);
+        SuggestionStore.handleEventPayload({
+            action: {
+                id,
+                type: ActionTypes.SUGGESTION_PRETEXT_CHANGED,
+                pretext,
+            },
+        });
+        assert.equal(SuggestionStore.suggestions.get(id).pretext, pretext);
+    });
+
+    test('should ignore events from unregistered suggestion boxes', () => {
+        const id = 'id1';
+        const pretext = 'pretext';
+        SuggestionStore.registerSuggestionBox(id);
+        SuggestionStore.unregisterSuggestionBox(id);
+
+        SuggestionStore.handleEventPayload({
+            action: {
+                id,
+                type: ActionTypes.SUGGESTION_PRETEXT_CHANGED,
+                pretext,
+            },
+        });
+        assert.equal(SuggestionStore.suggestions.has(id), false);
+    });
+});