diff --git a/BizHawk.Client.EmuHawk/MainForm.Events.cs b/BizHawk.Client.EmuHawk/MainForm.Events.cs
index 1fd8a6c2cf..2749213037 100644
--- a/BizHawk.Client.EmuHawk/MainForm.Events.cs
+++ b/BizHawk.Client.EmuHawk/MainForm.Events.cs
@@ -2066,9 +2066,9 @@ namespace BizHawk.Client.EmuHawk
 
 		private void GBCoreSettingsMenuItem_Click(object sender, EventArgs e)
 		{
-			if (Global.Emulator is Gameboy)
+			if (Global.Emulator is Gameboy gb)
 			{
-				GBPrefs.DoGBPrefsDialog(this);
+				GBPrefs.DoGBPrefsDialog(this, gb);
 			}
 			else // SameBoy
 			{
@@ -2340,7 +2340,10 @@ namespace BizHawk.Client.EmuHawk
 
 		private void DgbSettingsMenuItem_Click(object sender, EventArgs e)
 		{
-			DGBPrefs.DoDGBPrefsDialog(this);
+			if (Emulator is GambatteLink gambatte)
+			{
+				DGBPrefs.DoDGBPrefsDialog(this, gambatte);
+			}
 		}
 
 		private void DgbHawkSettingsMenuItem_Click(object sender, EventArgs e)
diff --git a/BizHawk.Client.EmuHawk/config/GB/DGBPrefs.cs b/BizHawk.Client.EmuHawk/config/GB/DGBPrefs.cs
index 3279dd3e17..7c025b9962 100644
--- a/BizHawk.Client.EmuHawk/config/GB/DGBPrefs.cs
+++ b/BizHawk.Client.EmuHawk/config/GB/DGBPrefs.cs
@@ -29,9 +29,8 @@ namespace BizHawk.Client.EmuHawk
 
 		private bool SyncSettingsChanged => gbPrefControl1.SyncSettingsChanged || gbPrefControl2.SyncSettingsChanged;
 
-		public static void DoDGBPrefsDialog(IWin32Window owner)
+		public static void DoDGBPrefsDialog(MainForm mainForm, GambatteLink gambatte)
 		{
-			var gambatte = (GambatteLink)Global.Emulator;
 			var s = gambatte.GetSettings();
 			var ss = gambatte.GetSyncSettings();
 
@@ -42,13 +41,13 @@ namespace BizHawk.Client.EmuHawk
 			dlg.gbPrefControl1.ColorGameBoy = emu.IsCGBMode(false);
 			dlg.gbPrefControl2.ColorGameBoy = emu.IsCGBMode(true);
 
-			if (dlg.ShowDialog(owner) == DialogResult.OK)
+			if (dlg.ShowDialog(mainForm) == DialogResult.OK)
 			{
 				dlg.GetSettings(out s, out ss);
 				gambatte.PutSettings(s);
 				if (dlg.SyncSettingsChanged)
 				{
-					GlobalWin.MainForm.PutCoreSyncSettings(ss);
+					mainForm.PutCoreSyncSettings(ss);
 				}
 			}
 		}
diff --git a/BizHawk.Client.EmuHawk/config/GB/GBPrefs.cs b/BizHawk.Client.EmuHawk/config/GB/GBPrefs.cs
index 3f619900c6..9020e4501e 100644
--- a/BizHawk.Client.EmuHawk/config/GB/GBPrefs.cs
+++ b/BizHawk.Client.EmuHawk/config/GB/GBPrefs.cs
@@ -1,7 +1,5 @@
 using System.Windows.Forms;
-
 using BizHawk.Emulation.Cores.Nintendo.Gameboy;
-using BizHawk.Client.Common;
 
 namespace BizHawk.Client.EmuHawk
 {
@@ -12,22 +10,21 @@ namespace BizHawk.Client.EmuHawk
 			InitializeComponent();
 		}
 
-		public static void DoGBPrefsDialog(IWin32Window owner)
+		public static void DoGBPrefsDialog(MainForm mainForm, Gameboy gb)
 		{
-			var gb = (Gameboy)Global.Emulator;
 			var s = gb.GetSettings();
 			var ss = gb.GetSyncSettings();
 
 			using var dlg = new GBPrefs();
 			dlg.gbPrefControl1.PutSettings(s, ss);
 			dlg.gbPrefControl1.ColorGameBoy = gb.IsCGBMode();
-			if (dlg.ShowDialog(owner) == DialogResult.OK)
+			if (dlg.ShowDialog(mainForm) == DialogResult.OK)
 			{
 				dlg.gbPrefControl1.GetSettings(out s, out ss);
 				gb.PutSettings(s);
 				if (dlg.gbPrefControl1.SyncSettingsChanged)
 				{
-					GlobalWin.MainForm.PutCoreSyncSettings(ss);
+					mainForm.PutCoreSyncSettings(ss);
 				}
 			}
 		}