diff --git a/src/BizHawk.Client.EmuHawk/MainForm.cs b/src/BizHawk.Client.EmuHawk/MainForm.cs
index 026c967804..5704631c71 100644
--- a/src/BizHawk.Client.EmuHawk/MainForm.cs
+++ b/src/BizHawk.Client.EmuHawk/MainForm.cs
@@ -1564,7 +1564,7 @@ namespace BizHawk.Client.EmuHawk
 			}
 
 			ofd.RestoreDirectory = true;
-			ofd.Filter = new FilesystemFilter("Libretro Cores", new[] { "dll" }).ToString();
+			ofd.Filter = new FilesystemFilter("Libretro Cores", new[] { OSTailoredCode.IsUnixHost ? "so" : "dll" }).ToString();
 
 			if (ofd.ShowDialog() == DialogResult.Cancel)
 			{
diff --git a/src/BizHawk.Emulation.Cores/Libretro/LibretroCore.cs b/src/BizHawk.Emulation.Cores/Libretro/LibretroCore.cs
index 960315e1c1..6c88fb1dd7 100644
--- a/src/BizHawk.Emulation.Cores/Libretro/LibretroCore.cs
+++ b/src/BizHawk.Emulation.Cores/Libretro/LibretroCore.cs
@@ -23,6 +23,8 @@ namespace BizHawk.Emulation.Cores.Libretro
 		// TODO: codepath just for introspection (lighter weight; no speex, no controls, etc.)
 		public LibretroCore(CoreComm nextComm, IGameInfo game, string corePath)
 		{
+			if (OSTailoredCode.IsUnixHost) throw new NotImplementedException("required library LibretroBridge is not yet available for Linux");
+
 			ServiceProvider = new BasicServiceProvider(this);
 			_SyncSettings = new SyncSettings();
 			CoreComm = nextComm;