diff --git a/src/calibre/customize/__init__.py b/src/calibre/customize/__init__.py
index 390325d669..6040031b3a 100644
--- a/src/calibre/customize/__init__.py
+++ b/src/calibre/customize/__init__.py
@@ -661,7 +661,6 @@ class InterfaceActionBase(Plugin):  # {{{
     supported_platforms = ['windows', 'osx', 'linux']
     author         = 'Kovid Goyal'
     type = _('User interface action')
-    can_be_disabled = False
 
     actual_plugin = None
 
@@ -696,7 +695,6 @@ class PreferencesPlugin(Plugin):  # {{{
     supported_platforms = ['windows', 'osx', 'linux']
     author         = 'Kovid Goyal'
     type = _('Preferences')
-    can_be_disabled = False
 
     #: Import path to module that contains a class named ConfigWidget
     #: which implements the ConfigWidgetInterface. Used by
diff --git a/src/calibre/customize/conversion.py b/src/calibre/customize/conversion.py
index 64158db28b..b5092bec57 100644
--- a/src/calibre/customize/conversion.py
+++ b/src/calibre/customize/conversion.py
@@ -133,7 +133,6 @@ class InputFormatPlugin(Plugin):
     '''
 
     type = _('Conversion input')
-    can_be_disabled = False
     supported_platforms = ['windows', 'osx', 'linux']
     commit_name = None  # unique name under which options for this plugin are saved
     ui_data = None
@@ -281,7 +280,6 @@ class OutputFormatPlugin(Plugin):
     '''
 
     type = _('Conversion output')
-    can_be_disabled = False
     supported_platforms = ['windows', 'osx', 'linux']
     commit_name = None  # unique name under which options for this plugin are saved
     ui_data = None
diff --git a/src/calibre/customize/ui.py b/src/calibre/customize/ui.py
index 3b9b9508fd..c58a1ff845 100644
--- a/src/calibre/customize/ui.py
+++ b/src/calibre/customize/ui.py
@@ -16,6 +16,7 @@ from calibre.customize import (
     CatalogPlugin,
     EditBookToolPlugin,
     FileTypePlugin,
+    InterfaceActionBase,
     InvalidPlugin,
     LibraryClosedPlugin,
     MetadataReaderPlugin,
@@ -105,7 +106,7 @@ def disable_plugin(plugin_or_name):
     plugin = find_plugin(x)
     if plugin is None:
         raise ValueError(f'No plugin named: {x} found')
-    if not plugin.can_be_disabled:
+    if not can_be_disabled(plugin):
         raise ValueError(f'Plugin {x} cannot be disabled')
     disable_plugin_by_name(x)
 
@@ -121,6 +122,26 @@ def enable_plugin(plugin_or_name):
     config['enabled_plugins'] = ep
 
 
+def is_internal_plugin(plugin_or_name):
+    x = getattr(plugin_or_name, 'name', plugin_or_name)
+    plugin = find_plugin(x)
+    return (plugin.installation_type is PluginInstallationType.BUILTIN
+            and isinstance(plugin, (
+                                    InterfaceActionBase,
+                                    PreferencesPlugin,
+                                    InputFormatPlugin,
+                                    OutputFormatPlugin,
+                                    InputProfile,
+                                    OutputProfile,
+                                )))
+
+
+def can_be_disabled(plugin_or_name):
+    x = getattr(plugin_or_name, 'name', plugin_or_name)
+    plugin = find_plugin(x)
+    return not is_internal_plugin(x) and plugin.can_be_disabled
+
+
 def restore_plugin_state_to_default(plugin_or_name):
     x = getattr(plugin_or_name, 'name', plugin_or_name)
     dp = config['disabled_plugins']
diff --git a/src/calibre/gui2/dialogs/plugin_updater.py b/src/calibre/gui2/dialogs/plugin_updater.py
index eb4fecfc79..a05b6762da 100644
--- a/src/calibre/gui2/dialogs/plugin_updater.py
+++ b/src/calibre/gui2/dialogs/plugin_updater.py
@@ -40,6 +40,7 @@ from calibre.customize.ui import (
     BLACKLISTED_PLUGINS,
     NameConflict,
     add_plugin,
+    can_be_disabled,
     disable_plugin,
     enable_plugin,
     has_external_plugins,
@@ -953,7 +954,7 @@ class PluginUpdaterDialog(SizePersistedDialog):
     def _toggle_enabled_clicked(self):
         display_plugin = self._selected_display_plugin()
         plugin = display_plugin.plugin
-        if not plugin.can_be_disabled:
+        if not can_be_disabled(plugin):
             return error_dialog(self, _('Plugin cannot be disabled'),
                          _('The plugin: %s cannot be disabled')%plugin.name, show=True)
         if is_disabled(plugin):
diff --git a/src/calibre/gui2/preferences/plugins.py b/src/calibre/gui2/preferences/plugins.py
index e1f3286639..6a246a91be 100644
--- a/src/calibre/gui2/preferences/plugins.py
+++ b/src/calibre/gui2/preferences/plugins.py
@@ -13,7 +13,17 @@ from qt.core import QAbstractItemModel, QAbstractItemView, QBrush, QDialog, QIco
 
 from calibre.constants import iswindows
 from calibre.customize import PluginInstallationType
-from calibre.customize.ui import NameConflict, add_plugin, disable_plugin, enable_plugin, initialized_plugins, is_disabled, plugin_customization, remove_plugin
+from calibre.customize.ui import (
+    NameConflict,
+    add_plugin,
+    can_be_disabled,
+    disable_plugin,
+    enable_plugin,
+    initialized_plugins,
+    is_disabled,
+    plugin_customization,
+    remove_plugin,
+)
 from calibre.gui2 import choose_files, error_dialog, gprefs, info_dialog, question_dialog
 from calibre.gui2.dialogs.confirm_delete import confirm
 from calibre.gui2.preferences import ConfigWidgetBase, test_widget
@@ -349,7 +359,7 @@ class ConfigWidget(ConfigWidgetBase, Ui_Form):
 
             plugin = self._plugin_model.index_to_plugin(index)
             if op == 'toggle':
-                if not plugin.can_be_disabled:
+                if not can_be_disabled(plugin):
                     info_dialog(self, _('Plugin cannot be disabled'),
                                  _('Disabling the plugin %s is not allowed')%plugin.name, show=True, show_copy_button=False)
                     return