diff --git a/app/assets/javascripts/gfm_auto_complete.js.es6 b/app/assets/javascripts/gfm_auto_complete.js.es6
index 7f1f2a5d278..0f6994dd2d1 100644
--- a/app/assets/javascripts/gfm_auto_complete.js.es6
+++ b/app/assets/javascripts/gfm_auto_complete.js.es6
@@ -103,6 +103,9 @@
       this.input.each((i, input) => {
         const $input = $(input);
         $input.off('focus.setupAtWho').on('focus.setupAtWho', this.setupAtWho.bind(this, $input));
+        // This triggers at.js again
+        // Needed for slash commands with suffixes (ex: /label ~)
+        $input.on('inserted-commands.atwho', $input.trigger.bind($input, 'keyup'));
       });
     },
     setupAtWho: function($input) {
diff --git a/changelogs/unreleased/27883-autocomplete-seems-to-not-trigger-when-at-character-is-part-of-an-autocompleted-text.yml b/changelogs/unreleased/27883-autocomplete-seems-to-not-trigger-when-at-character-is-part-of-an-autocompleted-text.yml
new file mode 100644
index 00000000000..52b7e96682d
--- /dev/null
+++ b/changelogs/unreleased/27883-autocomplete-seems-to-not-trigger-when-at-character-is-part-of-an-autocompleted-text.yml
@@ -0,0 +1,4 @@
+---
+title: Trigger autocomplete after selecting a slash command
+merge_request: 9117
+author:
diff --git a/spec/features/issues/gfm_autocomplete_spec.rb b/spec/features/issues/gfm_autocomplete_spec.rb
index 93139dc9e94..7135565294b 100644
--- a/spec/features/issues/gfm_autocomplete_spec.rb
+++ b/spec/features/issues/gfm_autocomplete_spec.rb
@@ -182,6 +182,20 @@ feature 'GFM autocomplete', feature: true, js: true do
       expect(page).not_to have_selector('.atwho-view')
     end
 
+    it 'triggers autocomplete after selecting a slash command' do
+      note = find('#note_note')
+      page.within '.timeline-content-form' do
+        note.native.send_keys('')
+        note.native.send_keys('/as')
+        note.click
+      end
+
+      find('.atwho-view li', text: '/assign').native.send_keys(:tab)
+
+      user_item = find('.atwho-view li', text: user.username)
+      expect(user_item).to have_content(user.username)
+    end
+
     def expect_to_wrap(should_wrap, item, note, value)
       expect(item).to have_content(value)
       expect(item).not_to have_content("\"#{value}\"")