diff --git a/src/BizHawk.Client.EmuHawk/ArgParser.cs b/src/BizHawk.Client.Common/ArgParser.cs
similarity index 73%
rename from src/BizHawk.Client.EmuHawk/ArgParser.cs
rename to src/BizHawk.Client.Common/ArgParser.cs
index 900a2bb7de..99d4ac9a1a 100644
--- a/src/BizHawk.Client.EmuHawk/ArgParser.cs
+++ b/src/BizHawk.Client.Common/ArgParser.cs
@@ -5,7 +5,7 @@ using System.Collections.Generic;
 using System.Linq;
 using System.IO;
 
-namespace BizHawk.Client.EmuHawk
+namespace BizHawk.Client.Common
 {
 	/// <summary>
 	/// Parses command line flags from a string array into various instance fields.
@@ -208,100 +208,10 @@ namespace BizHawk.Client.EmuHawk
 		{
 			return args.FirstOrDefault(arg => arg.StartsWith("--config=", StringComparison.InvariantCultureIgnoreCase))?.Substring(9);
 		}
-	}
 
-	public sealed class ArgParserException : Exception
-	{
-		public ArgParserException(string message) : base(message) {}
-	}
-
-	public readonly struct ParsedCLIFlags
-	{
-		public readonly string? cmdLoadSlot;
-
-		public readonly string? cmdLoadState;
-
-		public readonly string? cmdConfigPath;
-
-		public readonly string? cmdConfigFile;
-
-		public readonly string? cmdMovie;
-
-		public readonly string? cmdDumpType;
-
-		public readonly HashSet<int>? _currAviWriterFrameList;
-
-		public readonly int _autoDumpLength;
-
-		public readonly bool printVersion;
-
-		public readonly string? cmdDumpName;
-
-		public readonly bool _autoCloseOnDump;
-
-		public readonly bool _chromeless;
-
-		public readonly bool startFullscreen;
-
-		public readonly string? luaScript;
-
-		public readonly bool luaConsole;
-
-		public readonly (string IP, int Port)? SocketAddress;
-
-		public readonly string? MMFFilename;
-
-		public readonly (string? UrlGet, string? UrlPost)? HTTPAddresses;
-
-		public readonly bool? audiosync;
-
-		public readonly string? openExtToolDll;
-
-		public readonly string? cmdRom;
-
-		public ParsedCLIFlags(string? cmdLoadSlot,
-			string? cmdLoadState,
-			string? cmdConfigPath,
-			string? cmdConfigFile,
-			string? cmdMovie,
-			string? cmdDumpType,
-			HashSet<int>? currAviWriterFrameList,
-			int autoDumpLength,
-			bool printVersion,
-			string? cmdDumpName,
-			bool autoCloseOnDump,
-			bool chromeless,
-			bool startFullscreen,
-			string? luaScript,
-			bool luaConsole,
-			(string IP, int Port)? socketAddress,
-			string? mmfFilename,
-			(string? UrlGet, string? UrlPost)? httpAddresses,
-			bool? audiosync,
-			string? openExtToolDll,
-			string? cmdRom)
+		public sealed class ArgParserException : Exception
 		{
-			this.cmdLoadSlot = cmdLoadSlot;
-			this.cmdLoadState = cmdLoadState;
-			this.cmdConfigPath = cmdConfigPath;
-			this.cmdConfigFile = cmdConfigFile;
-			this.cmdMovie = cmdMovie;
-			this.cmdDumpType = cmdDumpType;
-			_currAviWriterFrameList = currAviWriterFrameList;
-			_autoDumpLength = autoDumpLength;
-			this.printVersion = printVersion;
-			this.cmdDumpName = cmdDumpName;
-			_autoCloseOnDump = autoCloseOnDump;
-			_chromeless = chromeless;
-			this.startFullscreen = startFullscreen;
-			this.luaScript = luaScript;
-			this.luaConsole = luaConsole;
-			SocketAddress = socketAddress;
-			MMFFilename = mmfFilename;
-			HTTPAddresses = httpAddresses;
-			this.audiosync = audiosync;
-			this.openExtToolDll = openExtToolDll;
-			this.cmdRom = cmdRom;
+			public ArgParserException(string message) : base(message) {}
 		}
 	}
 }
diff --git a/src/BizHawk.Client.Common/ParsedCLIFlags.cs b/src/BizHawk.Client.Common/ParsedCLIFlags.cs
new file mode 100644
index 0000000000..3e98e2b9af
--- /dev/null
+++ b/src/BizHawk.Client.Common/ParsedCLIFlags.cs
@@ -0,0 +1,96 @@
+#nullable enable
+
+using System.Collections.Generic;
+
+namespace BizHawk.Client.Common
+{
+	public readonly struct ParsedCLIFlags
+	{
+		public readonly string? cmdLoadSlot;
+
+		public readonly string? cmdLoadState;
+
+		public readonly string? cmdConfigPath;
+
+		public readonly string? cmdConfigFile;
+
+		public readonly string? cmdMovie;
+
+		public readonly string? cmdDumpType;
+
+		public readonly HashSet<int>? _currAviWriterFrameList;
+
+		public readonly int _autoDumpLength;
+
+		public readonly bool printVersion;
+
+		public readonly string? cmdDumpName;
+
+		public readonly bool _autoCloseOnDump;
+
+		public readonly bool _chromeless;
+
+		public readonly bool startFullscreen;
+
+		public readonly string? luaScript;
+
+		public readonly bool luaConsole;
+
+		public readonly (string IP, int Port)? SocketAddress;
+
+		public readonly string? MMFFilename;
+
+		public readonly (string? UrlGet, string? UrlPost)? HTTPAddresses;
+
+		public readonly bool? audiosync;
+
+		public readonly string? openExtToolDll;
+
+		public readonly string? cmdRom;
+
+		public ParsedCLIFlags(string? cmdLoadSlot,
+			string? cmdLoadState,
+			string? cmdConfigPath,
+			string? cmdConfigFile,
+			string? cmdMovie,
+			string? cmdDumpType,
+			HashSet<int>? currAviWriterFrameList,
+			int autoDumpLength,
+			bool printVersion,
+			string? cmdDumpName,
+			bool autoCloseOnDump,
+			bool chromeless,
+			bool startFullscreen,
+			string? luaScript,
+			bool luaConsole,
+			(string IP, int Port)? socketAddress,
+			string? mmfFilename,
+			(string? UrlGet, string? UrlPost)? httpAddresses,
+			bool? audiosync,
+			string? openExtToolDll,
+			string? cmdRom)
+		{
+			this.cmdLoadSlot = cmdLoadSlot;
+			this.cmdLoadState = cmdLoadState;
+			this.cmdConfigPath = cmdConfigPath;
+			this.cmdConfigFile = cmdConfigFile;
+			this.cmdMovie = cmdMovie;
+			this.cmdDumpType = cmdDumpType;
+			_currAviWriterFrameList = currAviWriterFrameList;
+			_autoDumpLength = autoDumpLength;
+			this.printVersion = printVersion;
+			this.cmdDumpName = cmdDumpName;
+			_autoCloseOnDump = autoCloseOnDump;
+			_chromeless = chromeless;
+			this.startFullscreen = startFullscreen;
+			this.luaScript = luaScript;
+			this.luaConsole = luaConsole;
+			SocketAddress = socketAddress;
+			MMFFilename = mmfFilename;
+			HTTPAddresses = httpAddresses;
+			this.audiosync = audiosync;
+			this.openExtToolDll = openExtToolDll;
+			this.cmdRom = cmdRom;
+		}
+	}
+}
diff --git a/src/BizHawk.Client.EmuHawk/MainForm.cs b/src/BizHawk.Client.EmuHawk/MainForm.cs
index 30f6e341fb..3a26987b2e 100644
--- a/src/BizHawk.Client.EmuHawk/MainForm.cs
+++ b/src/BizHawk.Client.EmuHawk/MainForm.cs
@@ -320,7 +320,7 @@ namespace BizHawk.Client.EmuHawk
 			{
 				ArgParser.ParseArguments(out _argParser, args);
 			}
-			catch (ArgParserException e)
+			catch (ArgParser.ArgParserException e)
 			{
 				MessageBox.Show(e.Message);
 			}