diff --git a/src/BizHawk.Emulation.Cores/Consoles/Nintendo/Gameboy/Gambatte.ISettable.cs b/src/BizHawk.Emulation.Cores/Consoles/Nintendo/Gameboy/Gambatte.ISettable.cs
index 5fc6d67065..94f96f850c 100644
--- a/src/BizHawk.Emulation.Cores/Consoles/Nintendo/Gameboy/Gambatte.ISettable.cs
+++ b/src/BizHawk.Emulation.Cores/Consoles/Nintendo/Gameboy/Gambatte.ISettable.cs
@@ -128,7 +128,7 @@ namespace BizHawk.Emulation.Cores.Nintendo.Gameboy
 			[DisplayName("Cart Bus Pull-Up Time")]
 			[Description("Time it takes for the cart bus to pull-up to 0xFF in CPU cycles. Used to account for differences in pull-up times between carts/consoles.")]
 			[DefaultValue(8)]
-			public uint CartBusPullUpTime { get; set; }
+			public int CartBusPullUpTime { get; set; }
 
 			[DisplayName("Realtime RTC")]
 			[Description("If true, the real time clock in MBC3 and HuC3 games will reflect real time, instead of emulated time.  Ignored (treated as false) when a movie is recording.")]
diff --git a/src/BizHawk.Emulation.Cores/Consoles/Nintendo/Gameboy/Gambatte.cs b/src/BizHawk.Emulation.Cores/Consoles/Nintendo/Gameboy/Gambatte.cs
index f1f97b20c2..e61631b580 100644
--- a/src/BizHawk.Emulation.Cores/Consoles/Nintendo/Gameboy/Gambatte.cs
+++ b/src/BizHawk.Emulation.Cores/Consoles/Nintendo/Gameboy/Gambatte.cs
@@ -196,7 +196,7 @@ namespace BizHawk.Emulation.Cores.Nintendo.Gameboy
 
 				LibGambatte.gambatte_setrtcdivisoroffset(GambatteState, _syncSettings.RTCDivisorOffset);
 
-				LibGambatte.gambatte_setcartbuspulluptime(GambatteState, _syncSettings.CartBusPullUpTime);
+				LibGambatte.gambatte_setcartbuspulluptime(GambatteState, (uint)_syncSettings.CartBusPullUpTime);
 
 				_cdCallback = new LibGambatte.CDCallback(CDCallbackProc);