diff --git a/Source/Core/Core/HW/SI_DeviceGCAdapter.cpp b/Source/Core/Core/HW/SI_DeviceGCAdapter.cpp
index c9b766c467..e68176ac3e 100644
--- a/Source/Core/Core/HW/SI_DeviceGCAdapter.cpp
+++ b/Source/Core/Core/HW/SI_DeviceGCAdapter.cpp
@@ -8,6 +8,7 @@
 #include "Common/MsgHandler.h"
 #include "Common/Logging/Log.h"
 #include "Core/ConfigManager.h"
+#include "Core/NetPlayProto.h"
 #include "Core/HW/GCPad.h"
 #include "Core/HW/SI_DeviceGCAdapter.h"
 #include "InputCommon/GCAdapter.h"
@@ -33,6 +34,27 @@ GCPadStatus CSIDevice_GCAdapter::GetPadStatus()
 	return PadStatus;
 }
 
+int CSIDevice_GCAdapter::RunBuffer(u8* buffer, int length)
+{
+	if (!NetPlay::IsNetPlayRunning())
+	{
+		// The previous check is a hack to prevent a netplay desync due to
+		// SI devices being different and returning different values on
+		// RunBuffer(); the corresponding code in GCAdapter.cpp has the same
+		// check.
+
+		// This returns an error value if there is no controller plugged
+		// into this port on the hardware gc adapter, exposing it to the game.
+		if (!GCAdapter::DeviceConnected(ISIDevice::m_iDeviceNumber))
+		{
+			TSIDevices device = SI_NONE;
+			memcpy(buffer, &device, sizeof(device));
+			return 4;
+		}
+	}
+	return CSIDevice_GCController::RunBuffer(buffer, length);
+}
+
 void CSIDevice_GCController::Rumble(u8 numPad, ControlState strength)
 {
 	SIDevices device = SConfig::GetInstance().m_SIDevice[numPad];
diff --git a/Source/Core/Core/HW/SI_DeviceGCAdapter.h b/Source/Core/Core/HW/SI_DeviceGCAdapter.h
index 16b94bf2ff..f073f318bf 100644
--- a/Source/Core/Core/HW/SI_DeviceGCAdapter.h
+++ b/Source/Core/Core/HW/SI_DeviceGCAdapter.h
@@ -14,4 +14,5 @@ public:
 	CSIDevice_GCAdapter(SIDevices device, int _iDeviceNumber);
 
 	GCPadStatus GetPadStatus() override;
+	int RunBuffer(u8* buffer, int length) override;
 };
diff --git a/Source/Core/InputCommon/GCAdapter.cpp b/Source/Core/InputCommon/GCAdapter.cpp
index eceed1ed0b..df71a8d846 100644
--- a/Source/Core/InputCommon/GCAdapter.cpp
+++ b/Source/Core/InputCommon/GCAdapter.cpp
@@ -12,6 +12,7 @@
 #include "Core/ConfigManager.h"
 #include "Core/Core.h"
 #include "Core/CoreTiming.h"
+#include "Core/NetPlayProto.h"
 #include "Core/HW/SI.h"
 #include "Core/HW/SystemTimers.h"
 
@@ -417,8 +418,11 @@ void Input(int chan, GCPadStatus* pad)
 			pad->triggerLeft = controller_payload_copy[1 + (9 * chan) + 7];
 			pad->triggerRight = controller_payload_copy[1 + (9 * chan) + 8];
 		}
-		else
+		else if (!NetPlay::IsNetPlayRunning())
 		{
+			// This is a hack to prevent a netplay desync due to SI devices
+			// being different and returning different values.
+			// The corresponding code in DeviceGCAdapter has the same check
 			pad->button = PAD_ERR_STATUS;
 		}
 	}