diff --git a/BizHawk.Client.EmuHawk/tools/Lua/LuaConsole.cs b/BizHawk.Client.EmuHawk/tools/Lua/LuaConsole.cs
index 868ec4742f..70fe452a22 100644
--- a/BizHawk.Client.EmuHawk/tools/Lua/LuaConsole.cs
+++ b/BizHawk.Client.EmuHawk/tools/Lua/LuaConsole.cs
@@ -678,7 +678,7 @@ namespace BizHawk.Client.EmuHawk
 
 		private static void UpdateRegisteredFunctionsDialog()
 		{
-			foreach (var form in Application.OpenForms.OfType<LuaRegisteredFunctionsList>())
+			foreach (var form in Application.OpenForms.OfType<LuaRegisteredFunctionsList>().ToList())
 			{
 				form.UpdateValues();
 			}