diff --git a/app/models/application_setting.rb b/app/models/application_setting.rb
index f266e7db6da..5e16badabec 100644
--- a/app/models/application_setting.rb
+++ b/app/models/application_setting.rb
@@ -420,7 +420,7 @@ class ApplicationSetting < ActiveRecord::Base
   #   the enabling/disabling is `performance_bar_allowed_group_id`
   # - If `enable` is false, we set `performance_bar_allowed_group_id` to `nil`
   def performance_bar_enabled=(enable)
-    return if enable
+    return if Gitlab::Utils.to_boolean(enable)
 
     self.performance_bar_allowed_group_id = nil
   end
diff --git a/changelogs/unreleased/39570-performance-bar-appears-enabled-even-though-it-won-t-show-up.yml b/changelogs/unreleased/39570-performance-bar-appears-enabled-even-though-it-won-t-show-up.yml
new file mode 100644
index 00000000000..66939d89d69
--- /dev/null
+++ b/changelogs/unreleased/39570-performance-bar-appears-enabled-even-though-it-won-t-show-up.yml
@@ -0,0 +1,5 @@
+---
+title: Allow to disable the Performance Bar
+merge_request: 15084
+author:
+type: fixed
diff --git a/doc/administration/monitoring/performance/performance_bar.md b/doc/administration/monitoring/performance/performance_bar.md
index 68efe0aae5c..b9464945cea 100644
--- a/doc/administration/monitoring/performance/performance_bar.md
+++ b/doc/administration/monitoring/performance/performance_bar.md
@@ -28,6 +28,12 @@ will be allowed to display the Performance Bar.
 Make sure _Enable the Performance Bar_ is checked and hit
 **Save** to save the changes.
 
+Once the Performance Bar is enabled, you will need to press the [<kbd>p</kbd> +
+<kbd>b</kbd> keyboard shortcut](../../../workflow/shortcuts.md) to actually
+display it.
+
+You can toggle the Bar using the same shortcut.
+
 ---
 
 ![GitLab Performance Bar Admin Settings](img/performance_bar_configuration_settings.png)
diff --git a/doc/workflow/shortcuts.md b/doc/workflow/shortcuts.md
index 87416008e98..2e1bd6bfe5c 100644
--- a/doc/workflow/shortcuts.md
+++ b/doc/workflow/shortcuts.md
@@ -9,7 +9,7 @@ You can see GitLab's keyboard shortcuts by using 'shift + ?'
 | <kbd>n</kbd> | Main navigation |
 | <kbd>s</kbd> | Focus search |
 | <kbd>f</kbd> | Focus filter |
-| <kbd>p b</kbd> | Show/hide the Performance Bar |
+| <kbd>p</kbd> + <kbd>b</kbd> | Show/hide the Performance Bar |
 | <kbd>?</kbd> | Show/hide this dialog |
 | <kbd>⌘</kbd> + <kbd>shift</kbd> + <kbd>p</kbd> | Toggle markdown preview |
 | <kbd>↑</kbd> | Edit last comment (when focused on an empty textarea) |
diff --git a/spec/features/admin/admin_settings_spec.rb b/spec/features/admin/admin_settings_spec.rb
index c490dce7ab0..85561511101 100644
--- a/spec/features/admin/admin_settings_spec.rb
+++ b/spec/features/admin/admin_settings_spec.rb
@@ -95,6 +95,29 @@ feature 'Admin updates settings' do
     expect(find_field('ED25519 SSH keys').value).to eq(forbidden)
   end
 
+  scenario 'Change Performance Bar settings' do
+    group = create(:group)
+
+    check 'Enable the Performance Bar'
+    fill_in 'Allowed group', with: group.path
+
+    click_on 'Save'
+
+    expect(page).to have_content 'Application settings saved successfully'
+
+    expect(find_field('Enable the Performance Bar')).to be_checked
+    expect(find_field('Allowed group').value).to eq group.path
+
+    uncheck 'Enable the Performance Bar'
+
+    click_on 'Save'
+
+    expect(page).to have_content 'Application settings saved successfully'
+
+    expect(find_field('Enable the Performance Bar')).not_to be_checked
+    expect(find_field('Allowed group').value).to be_nil
+  end
+
   def check_all_events
     page.check('Active')
     page.check('Push')