diff --git a/LEGO1/mxdirect3d.cpp b/LEGO1/mxdirect3d.cpp
index 544252aa..517a9aad 100644
--- a/LEGO1/mxdirect3d.cpp
+++ b/LEGO1/mxdirect3d.cpp
@@ -122,6 +122,28 @@ BOOL MxDirect3D::D3DSetMode()
 	return TRUE;
 }
 
+// FUNCTION: LEGO1 0x1009b5a0
+DWORD MxDirect3D::GetZBufferBitDepth(MxAssignedDevice* p_assignedDevice)
+{
+	DWORD bitDepth;
+
+	if (p_assignedDevice->m_desc.dwFlags & D3DDD_DEVICEZBUFFERBITDEPTH)
+		bitDepth = p_assignedDevice->m_desc.dwDeviceZBufferBitDepth;
+	else
+		bitDepth = 0;
+
+	if (bitDepth & DDBD_32)
+		return 32;
+	if (bitDepth & DDBD_24)
+		return 24;
+	if (bitDepth & DDBD_16)
+		return 16;
+	if (bitDepth & DDBD_8)
+		return 8;
+
+	return -1;
+}
+
 // FUNCTION: LEGO1 0x1009b5f0
 BOOL MxDirect3D::SetDevice(MxDeviceEnumerate& p_deviceEnumerate, MxDriver* p_driver, MxDevice* p_device)
 {
diff --git a/LEGO1/mxdirect3d.h b/LEGO1/mxdirect3d.h
index 4877159b..8ad41593 100644
--- a/LEGO1/mxdirect3d.h
+++ b/LEGO1/mxdirect3d.h
@@ -23,7 +23,7 @@ public:
 
 	friend class MxDirect3D;
 
-private:
+public:
 	GUID m_guid;                                 // 0x00
 	MxU32 m_flags;                               // 0x10
 	D3DDEVICEDESC m_desc;                        // 0x14
@@ -57,6 +57,7 @@ public:
 
 	BOOL CreateIDirect3D();
 	BOOL D3DSetMode();
+	DWORD GetZBufferBitDepth(MxAssignedDevice* p_assignedDevice);
 	BOOL SetDevice(MxDeviceEnumerate& p_deviceEnumerate, MxDriver* p_driver, MxDevice* p_device);
 
 	inline MxAssignedDevice* GetAssignedDevice() { return this->m_assignedDevice; };