diff --git a/src/octoprint/plugins/pluginmanager/__init__.py b/src/octoprint/plugins/pluginmanager/__init__.py
index 091f4a97..48a7be6d 100644
--- a/src/octoprint/plugins/pluginmanager/__init__.py
+++ b/src/octoprint/plugins/pluginmanager/__init__.py
@@ -337,8 +337,11 @@ class PluginManagerPlugin(octoprint.plugin.SimpleApiPlugin,
 			self._send_result_notification("install", result)
 			return jsonify(result)
 
-		self._plugin_manager.mark_plugin(new_plugin_key, uninstalled=False)
 		self._plugin_manager.reload_plugins()
+		is_reinstall = self._plugin_manager.is_plugin_marked(new_plugin_key, "uninstalled")
+		self._plugin_manager.mark_plugin(new_plugin_key,
+		                                 uninstalled=False,
+		                                 installed=not is_reinstall)
 
 		needs_restart = self._plugin_manager.is_restart_needing_plugin(new_plugin) or new_plugin_key in all_plugins_before or reinstall is not None
 		needs_refresh = new_plugin.implementation and isinstance(new_plugin.implementation, octoprint.plugin.ReloadNeedingPlugin)
@@ -351,10 +354,13 @@ class PluginManagerPlugin(octoprint.plugin.SimpleApiPlugin,
 
 	def command_uninstall(self, plugin):
 		if plugin.key == "pluginmanager":
-			return make_response("Can't uninstall Plugin Manager", 400)
+			return make_response("Can't uninstall Plugin Manager", 403)
+
+		if not plugin.managable:
+			return make_response("Plugin is not managable and hence cannot be uninstalled", 403)
 
 		if plugin.bundled:
-			return make_response("Bundled plugins cannot be uninstalled", 400)
+			return make_response("Bundled plugins cannot be uninstalled", 403)
 
 		if plugin.origin is None:
 			self._logger.warn(u"Trying to uninstall plugin {plugin} but origin is unknown".format(**locals()))
@@ -398,7 +404,8 @@ class PluginManagerPlugin(octoprint.plugin.SimpleApiPlugin,
 		needs_restart = self._plugin_manager.is_restart_needing_plugin(plugin)
 		needs_refresh = plugin.implementation and isinstance(plugin.implementation, octoprint.plugin.ReloadNeedingPlugin)
 
-		self._plugin_manager.mark_plugin(plugin.key, uninstalled=True)
+		was_pending_install = self._plugin_manager.is_plugin_marked(plugin.key, "installed")
+		self._plugin_manager.mark_plugin(plugin.key, uninstalled=not was_pending_install, installed=False)
 
 		if not needs_restart:
 			try:
@@ -670,11 +677,12 @@ class PluginManagerPlugin(octoprint.plugin.SimpleApiPlugin,
 			url=plugin.url,
 			license=plugin.license,
 			bundled=plugin.bundled,
+			managable=plugin.managable,
 			enabled=plugin.enabled,
 			pending_enable=(not plugin.enabled and plugin.key in self._pending_enable),
 			pending_disable=(plugin.enabled and plugin.key in self._pending_disable),
-			pending_install=(plugin.key in self._pending_install),
-			pending_uninstall=(plugin.key in self._pending_uninstall),
+			pending_install=(self._plugin_manager.is_plugin_marked(plugin.key, "installed")),
+			pending_uninstall=(self._plugin_manager.is_plugin_marked(plugin.key, "uninstalled")),
 			origin=plugin.origin.type
 		)
 
diff --git a/src/octoprint/plugins/pluginmanager/templates/pluginmanager_settings.jinja2 b/src/octoprint/plugins/pluginmanager/templates/pluginmanager_settings.jinja2
index 014d75a4..72cbc7ca 100644
--- a/src/octoprint/plugins/pluginmanager/templates/pluginmanager_settings.jinja2
+++ b/src/octoprint/plugins/pluginmanager/templates/pluginmanager_settings.jinja2
@@ -42,7 +42,7 @@
     <tbody data-bind="foreach: plugins.paginatedItems">
     <tr>
         <td class="settings_plugin_plugin_manager_plugins_name">
-            <div data-bind="css: {muted: !enabled}"><span data-bind="text: name"></span> <span data-bind="visible: version">(<span data-bind="text: version"></span>)</span> <i title="{{ _('Bundled') }}" class="icon-th-large" data-bind="visible: bundled"></i> <i title="Restart needed" class="icon-refresh" data-bind="visible: pending_enable || pending_disable || pending_uninstall"></i> <i title="Uninstalled" class="icon-remove" data-bind="visible: pending_uninstall"></i></div>
+            <div data-bind="css: {muted: !enabled}"><span data-bind="text: name"></span> <span data-bind="visible: version">(<span data-bind="text: version"></span>)</span> <i title="{{ _('Bundled with OctoPrint') }}" class="icon-th-large" data-bind="visible: bundled"></i> <i class="icon-lock" title="{{ _('Cannot be uninstalled through OctoPrint') }}" data-bind="visible: !managable"></i> <i title="{{ _('Restart of OctoPrint needed for changes to take effect') }}" class="icon-refresh" data-bind="visible: pending_enable || pending_disable || pending_install || pending_uninstall"></i> <i title="{{ _('Pending install') }}" class="icon-plus" data-bind="visible: pending_install"></i> <i title="{{ _('Pending uninstall') }}" class="icon-minus" data-bind="visible: pending_uninstall"></i></div>
             <div><small class="muted" data-bind="text: description">&nbsp;</small></div>
             <div data-bind="css: {muted: !enabled}">
                 <small data-bind="visible: url"><i class="icon-home"></i> <a data-bind="attr: {href: url}">{{ _('Homepage') }}</a></small>