diff --git a/src/modules/launcher/PowerLauncher/Plugin/PluginManager.cs b/src/modules/launcher/PowerLauncher/Plugin/PluginManager.cs
index 8280527abc..12e2a3cfd7 100644
--- a/src/modules/launcher/PowerLauncher/Plugin/PluginManager.cs
+++ b/src/modules/launcher/PowerLauncher/Plugin/PluginManager.cs
@@ -24,6 +24,7 @@ namespace PowerLauncher.Plugin
     {
         private static readonly IFileSystem FileSystem = new FileSystem();
         private static readonly IDirectory Directory = FileSystem.Directory;
+        private static readonly object AllPluginsLock = new object();
 
         private static IEnumerable<PluginPair> _contextMenuPlugins = new List<PluginPair>();
 
@@ -44,7 +45,13 @@ namespace PowerLauncher.Plugin
             {
                 if (_allPlugins == null)
                 {
-                    _allPlugins = PluginsLoader.Plugins(PluginConfig.Parse(Directories));
+                    lock (AllPluginsLock)
+                    {
+                        if (_allPlugins == null)
+                        {
+                            _allPlugins = PluginsLoader.Plugins(PluginConfig.Parse(Directories));
+                        }
+                    }
                 }
 
                 return _allPlugins;
diff --git a/src/modules/launcher/PowerLauncher/Plugin/PluginsLoader.cs b/src/modules/launcher/PowerLauncher/Plugin/PluginsLoader.cs
index 44434135ad..2b51e114e0 100644
--- a/src/modules/launcher/PowerLauncher/Plugin/PluginsLoader.cs
+++ b/src/modules/launcher/PowerLauncher/Plugin/PluginsLoader.cs
@@ -27,7 +27,9 @@ namespace PowerLauncher.Plugin
         public static IEnumerable<PluginPair> CSharpPlugins(List<PluginMetadata> source)
         {
             var plugins = new List<PluginPair>();
-            var metadatas = source.Where(o => o.Language.ToUpperInvariant() == AllowedLanguage.CSharp);
+            var metadatas = source
+                .Where(o => o.Language.ToUpperInvariant() == AllowedLanguage.CSharp)
+                .ToList();
 
             foreach (var metadata in metadatas)
             {