diff --git a/source/Configuration/PropertySheetHelper.cpp b/source/Configuration/PropertySheetHelper.cpp
index c8c7a6cb..51bcad30 100644
--- a/source/Configuration/PropertySheetHelper.cpp
+++ b/source/Configuration/PropertySheetHelper.cpp
@@ -36,6 +36,7 @@ Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 #include "../Interface.h"
 #include "../Uthernet2.h"
 #include "../Tfe/PCapBackend.h"
+#include "../CmdLine.h"
 
 /*
 Config causing AfterClose msgs:
@@ -134,6 +135,8 @@ void CPropertySheetHelper::SetSlot(UINT slot, SS_CARDTYPE newCardType)
 
 	GetCardMgr().Insert(slot, newCardType);
 	GetCardMgr().GetRef(slot).InitializeIO(GetCxRomPeripheral());
+	if (newCardType == CT_GenericHDD)
+		dynamic_cast<HarddiskInterfaceCard&>(GetCardMgr().GetRef(slot)).SetUserNumBlocks(g_cmdLine.uHarddiskNumBlocks);
 }
 
 // Used by:
diff --git a/source/Harddisk.cpp b/source/Harddisk.cpp
index 21098a49..0a0ddc57 100644
--- a/source/Harddisk.cpp
+++ b/source/Harddisk.cpp
@@ -37,7 +37,6 @@ Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 #include "Registry.h"
 #include "SaveState.h"
 #include "YamlHelper.h"
-#include "CmdLine.h"
 
 #include "Debugger/Debug.h"
 #include "../resource/resource.h"
@@ -677,13 +676,13 @@ BYTE __stdcall HarddiskInterfaceCard::IORead(WORD pc, WORD addr, BYTE bWrite, BY
 		break;
 	case 0x9:
 		if (pHDD->m_imageloaded)
-			r = (BYTE)(GetImageSizeInBlocks(pHDD->m_imagehandle) & 0x00ff);
+			r = (BYTE)(pCard->GetImageSizeInBlocks(pHDD->m_imagehandle) & 0x00ff);
 		else
 			r = 0;
 		break;
 	case 0xa:
 		if (pHDD->m_imageloaded)
-			r = (BYTE)((GetImageSizeInBlocks(pHDD->m_imagehandle) & 0xff00) >> 8);
+			r = (BYTE)((pCard->GetImageSizeInBlocks(pHDD->m_imagehandle) & 0xff00) >> 8);
 		else
 			r = 0;
 		break;
@@ -750,8 +749,8 @@ BYTE __stdcall HarddiskInterfaceCard::IOWrite(WORD pc, WORD addr, BYTE bWrite, B
 
 UINT HarddiskInterfaceCard::GetImageSizeInBlocks(ImageInfo* const pImageInfo)
 {
-	if (g_cmdLine.uHarddiskNumBlocks != 0)
-		return g_cmdLine.uHarddiskNumBlocks;
+	if (m_userNumBlocks != 0)
+		return m_userNumBlocks;
 	UINT numberOfBlocks = (pImageInfo ? pImageInfo->uImageSize : 0) / HD_BLOCK_SIZE;
 	if (numberOfBlocks > kHarddiskMaxNumBlocks)
 		numberOfBlocks = kHarddiskMaxNumBlocks;
diff --git a/source/Harddisk.h b/source/Harddisk.h
index fc71d93d..048f0051 100644
--- a/source/Harddisk.h
+++ b/source/Harddisk.h
@@ -100,6 +100,7 @@ public:
 	void Unplug(const int iDrive);
 	bool IsDriveUnplugged(const int iDrive);
 	void LoadLastDiskImage(const int iDrive);
+	void SetUserNumBlocks(UINT numBlocks) { m_userNumBlocks = numBlocks; }
 
 	void GetLightStatus(Disk_Status_e* pDisk1Status);
 	bool ImageSwap(void);
@@ -119,7 +120,7 @@ private:
 	const std::string& DiskGetBaseName(const int iDrive);
 	bool SelectImage(const int drive, LPCSTR pszFilename);
 	void UpdateLightStatus(HardDiskDrive* pHDD);
-	static UINT GetImageSizeInBlocks(ImageInfo* const pImageInfo);
+	UINT GetImageSizeInBlocks(ImageInfo* const pImageInfo);
 	void SaveSnapshotHDDUnit(YamlSaveHelper& yamlSaveHelper, UINT unit);
 	bool LoadSnapshotHDDUnit(YamlLoadHelper& yamlLoadHelper, UINT unit);
 
@@ -128,6 +129,7 @@ private:
 	BYTE m_unitNum;			// b7=unit
 	BYTE m_command;
 	UINT64 m_notBusyCycle;
+	UINT m_userNumBlocks;
 
 	bool m_saveDiskImage;	// Save the DiskImage name to Registry
 
diff --git a/source/Windows/AppleWin.cpp b/source/Windows/AppleWin.cpp
index a1ec1818..0f711cff 100644
--- a/source/Windows/AppleWin.cpp
+++ b/source/Windows/AppleWin.cpp
@@ -802,6 +802,8 @@ static void RepeatInitialization(void)
 		{
 			if (GetCardMgr().QuerySlot(i) == CT_Disk2 && g_cmdLine.slotInfo[i].isDiskII13)
 				dynamic_cast<Disk2InterfaceCard&>(GetCardMgr().GetRef(i)).SetFirmware13Sector();
+			if (GetCardMgr().QuerySlot(i) == CT_GenericHDD)
+				dynamic_cast<HarddiskInterfaceCard&>(GetCardMgr().GetRef(i)).SetUserNumBlocks(g_cmdLine.uHarddiskNumBlocks);
 		}
 
 		// Create window after inserting/removing VidHD card (as it affects width & height)