diff --git a/channels/printer/client/win/printer_win.c b/channels/printer/client/win/printer_win.c
index c92b60249..213a6aec5 100644
--- a/channels/printer/client/win/printer_win.c
+++ b/channels/printer/client/win/printer_win.c
@@ -104,18 +104,20 @@ static WCHAR* printer_win_get_printjob_name(size_t id)
  */
 static UINT printer_win_write_printjob(rdpPrintJob* printjob, const BYTE* data, size_t size)
 {
-	rdpWinPrinter* printer;
 	LPCVOID pBuf = data;
-	DWORD cbBuf = size;
-	DWORD pcWritten;
+	DWORD pcWritten = 0;
+
+	if (size > UINT32_MAX)
+		return ERROR_BAD_ARGUMENTS;
 
 	if (!printjob || !data)
 		return ERROR_BAD_ARGUMENTS;
 
-	printer = (rdpWinPrinter*)printjob->printer;
+	rdpWinPrinter* printer = (rdpWinPrinter*)printjob->printer;
 	if (!printer)
 		return ERROR_BAD_ARGUMENTS;
 
+	DWORD cbBuf = WINPR_ASSERTING_INT_CAST(uint32_t, size);
 	if (!WritePrinter(printer->hPrinter, pBuf, cbBuf, &pcWritten))
 		return ERROR_INTERNAL_ERROR;
 	return CHANNEL_RC_OK;
diff --git a/channels/rdpdr/client/rdpdr_main.c b/channels/rdpdr/client/rdpdr_main.c
index 67feb00db..ebe5ad233 100644
--- a/channels/rdpdr/client/rdpdr_main.c
+++ b/channels/rdpdr/client/rdpdr_main.c
@@ -361,7 +361,6 @@ static LRESULT CALLBACK hotplug_proc(HWND hWnd, UINT Msg, WPARAM wParam, LPARAM
 					{
 						PDEV_BROADCAST_VOLUME lpdbv = (PDEV_BROADCAST_VOLUME)lpdb;
 						DWORD unitmask = lpdbv->dbcv_unitmask;
-						int count;
 						char drive_name_upper, drive_name_lower;
 						ULONG_PTR* keys = NULL;
 						DEVICE_DRIVE_EXT* device_ext;
@@ -373,9 +372,10 @@ static LRESULT CALLBACK hotplug_proc(HWND hWnd, UINT Msg, WPARAM wParam, LPARAM
 							{
 								drive_name_upper = 'A' + i;
 								drive_name_lower = 'a' + i;
-								count = ListDictionary_GetKeys(rdpdr->devman->devices, &keys);
+								const size_t count =
+								    ListDictionary_GetKeys(rdpdr->devman->devices, &keys);
 
-								for (int j = 0; j < count; j++)
+								for (size_t j = 0; j < count; j++)
 								{
 									device_ext = (DEVICE_DRIVE_EXT*)ListDictionary_GetItemValue(
 									    rdpdr->devman->devices, (void*)keys[j]);
@@ -388,8 +388,9 @@ static LRESULT CALLBACK hotplug_proc(HWND hWnd, UINT Msg, WPARAM wParam, LPARAM
 									{
 										if (device_ext->automount)
 										{
-											devman_unregister_device(rdpdr->devman, (void*)keys[j]);
-											ids[0] = keys[j];
+											ULONG_PTR key = keys[j];
+											devman_unregister_device(rdpdr->devman, (void*)key);
+											ids[0] = WINPR_ASSERTING_INT_CAST(uint32_t, key);
 
 											if ((error = rdpdr_send_device_list_remove_request(
 											         rdpdr, 1, ids)))
diff --git a/channels/urbdrc/client/data_transfer.c b/channels/urbdrc/client/data_transfer.c
index 19dabb693..768c5446b 100644
--- a/channels/urbdrc/client/data_transfer.c
+++ b/channels/urbdrc/client/data_transfer.c
@@ -29,6 +29,7 @@
 
 #include "urbdrc_types.h"
 #include "data_transfer.h"
+#include "msusb.h"
 
 static void usb_process_get_port_status(IUDEVICE* pdev, wStream* out)
 {
diff --git a/channels/urbdrc/client/libusb/libusb_udevice.c b/channels/urbdrc/client/libusb/libusb_udevice.c
index cf358cfec..8cdfe9ee8 100644
--- a/channels/urbdrc/client/libusb/libusb_udevice.c
+++ b/channels/urbdrc/client/libusb/libusb_udevice.c
@@ -31,6 +31,7 @@
 #include <errno.h>
 
 #include "libusb_udevice.h"
+#include "msusb.h"
 #include "../common/urbdrc_types.h"
 
 #define BASIC_STATE_FUNC_DEFINED(_arg, _type)             \
diff --git a/channels/urbdrc/client/libusb/libusb_udevice.h b/channels/urbdrc/client/libusb/libusb_udevice.h
index ac12abf43..3a1fbdb78 100644
--- a/channels/urbdrc/client/libusb/libusb_udevice.h
+++ b/channels/urbdrc/client/libusb/libusb_udevice.h
@@ -26,6 +26,7 @@
 
 #include "urbdrc_types.h"
 #include "urbdrc_main.h"
+#include "msusb.h"
 
 typedef struct libusb_device LIBUSB_DEVICE;
 typedef struct libusb_device_handle LIBUSB_DEVICE_HANDLE;
diff --git a/client/Windows/wf_client.c b/client/Windows/wf_client.c
index df969a80a..e97f4a015 100644
--- a/client/Windows/wf_client.c
+++ b/client/Windows/wf_client.c
@@ -283,7 +283,11 @@ static BOOL wf_pre_connect(freerdp* instance)
 		}
 
 		if (keyboardLayoutId == 0)
-			keyboardLayoutId = ((DWORD)GetKeyboardLayout(0) >> 16) & 0x0000FFFF;
+		{
+			const HKL layout = GetKeyboardLayout(0);
+			const uint32_t masked = (uint32_t)(((uintptr_t)layout >> 16) & 0xFFFF);
+			keyboardLayoutId = masked;
+		}
 	}
 
 	if (keyboardLayoutId == 0)
diff --git a/client/Windows/wf_cliprdr.c b/client/Windows/wf_cliprdr.c
index beddce8f9..9335772a0 100644
--- a/client/Windows/wf_cliprdr.c
+++ b/client/Windows/wf_cliprdr.c
@@ -2096,9 +2096,10 @@ static SSIZE_T wf_cliprdr_get_filedescriptor(wfClipboard* clipboard, BYTE** pDat
 		for (char* p = (char*)((char*)dropFiles + dropFiles->pFiles); (len = strlen(p)) > 0;
 		     p += len + 1, clipboard->nFiles++)
 		{
-			const int cchWideChar = MultiByteToWideChar(CP_ACP, MB_COMPOSITE, p, len, NULL, 0);
+			const int ilen = WINPR_ASSERTING_INT_CAST(int, len);
+			const int cchWideChar = MultiByteToWideChar(CP_ACP, MB_COMPOSITE, p, ilen, NULL, 0);
 			WCHAR* wFileName = (LPWSTR)calloc(cchWideChar, sizeof(WCHAR));
-			MultiByteToWideChar(CP_ACP, MB_COMPOSITE, p, len, wFileName, cchWideChar);
+			MultiByteToWideChar(CP_ACP, MB_COMPOSITE, p, ilen, wFileName, cchWideChar);
 			wf_cliprdr_process_filename(clipboard, wFileName, cchWideChar);
 			free(wFileName);
 		}
@@ -2139,8 +2140,6 @@ static UINT
 wf_cliprdr_server_format_data_request(CliprdrClientContext* context,
                                       const CLIPRDR_FORMAT_DATA_REQUEST* formatDataRequest)
 {
-	CLIPRDR_FORMAT_DATA_RESPONSE response = { 0 };
-
 	if (!context || !formatDataRequest)
 		return ERROR_INTERNAL_ERROR;
 
@@ -2150,25 +2149,28 @@ wf_cliprdr_server_format_data_request(CliprdrClientContext* context,
 		return ERROR_INTERNAL_ERROR;
 
 	const UINT32 requestedFormatId = formatDataRequest->requestedFormatId;
-
+	BYTE* requestedFormatData = NULL;
+	SSIZE_T res = 0;
 	if (requestedFormatId == RegisterClipboardFormat(CFSTR_FILEDESCRIPTORW))
 	{
-		const SSIZE_T res = wf_cliprdr_get_filedescriptor(clipboard, &response.requestedFormatData);
-		if (res > 0)
-			response.common.dataLen = (UINT32)res;
+		res = wf_cliprdr_get_filedescriptor(clipboard, &requestedFormatData);
 	}
 	else
 	{
-		const SSIZE_T res =
-		    wf_cliprdr_tryopen(clipboard, requestedFormatId, &response.requestedFormatData);
-		if (res > 0)
-			response.common.dataLen = (UINT32)res;
+		res = wf_cliprdr_tryopen(clipboard, requestedFormatId, &requestedFormatData);
 	}
 
-	response.common.msgFlags = CB_RESPONSE_OK;
+	UINT rc = ERROR_INTERNAL_ERROR;
+	if (res >= 0)
+	{
+		CLIPRDR_FORMAT_DATA_RESPONSE response = { .common = { .msgType = CB_FORMAT_DATA_RESPONSE,
+			                                                  .msgFlags = CB_RESPONSE_OK,
+			                                                  .dataLen = (uint32_t)res },
+			                                      .requestedFormatData = requestedFormatData };
 
-	const UINT rc = clipboard->context->ClientFormatDataResponse(clipboard->context, &response);
-	free(response.requestedFormatData);
+		rc = clipboard->context->ClientFormatDataResponse(clipboard->context, &response);
+	}
+	free(requestedFormatData);
 	return rc;
 }
 
diff --git a/client/Windows/wf_floatbar.c b/client/Windows/wf_floatbar.c
index f91047ce2..a9d9a67aa 100644
--- a/client/Windows/wf_floatbar.c
+++ b/client/Windows/wf_floatbar.c
@@ -379,7 +379,9 @@ static BOOL floatbar_paint(wfFloatBar* const floatbar, const HDC hdc)
 	LineTo(hdc, right + 1, top - 1);
 	DeleteObject(hpen);
 	SelectObject(hdc, orig);
-	DrawText(hdc, floatbar->wfc->window_title, wcslen(floatbar->wfc->window_title),
+
+	const size_t wlen = wcslen(floatbar->wfc->window_title);
+	DrawText(hdc, floatbar->wfc->window_title, WINPR_ASSERTING_INT_CAST(int, wlen),
 	         &floatbar->textRect,
 	         DT_CENTER | DT_VCENTER | DT_END_ELLIPSIS | DT_NOPREFIX | DT_SINGLELINE);
 
diff --git a/libfreerdp/core/gateway/rpc_client.c b/libfreerdp/core/gateway/rpc_client.c
index f30454019..784301c36 100644
--- a/libfreerdp/core/gateway/rpc_client.c
+++ b/libfreerdp/core/gateway/rpc_client.c
@@ -1008,8 +1008,9 @@ int rpc_in_channel_send_pdu(RpcInChannel* inChannel, const BYTE* buffer, size_t
 
 	if (header.ptype == PTYPE_REQUEST)
 	{
-		inChannel->BytesSent += status;
-		inChannel->SenderAvailableWindow -= status;
+		const uint32_t ustatus = WINPR_ASSERTING_INT_CAST(uint32_t, status);
+		inChannel->BytesSent += ustatus;
+		inChannel->SenderAvailableWindow -= ustatus;
 	}
 
 	if (status > INT32_MAX)
diff --git a/libfreerdp/core/server.c b/libfreerdp/core/server.c
index 4a9e12e99..71abd4cc2 100644
--- a/libfreerdp/core/server.c
+++ b/libfreerdp/core/server.c
@@ -1638,7 +1638,7 @@ BOOL WINAPI FreeRDP_WTSVirtualChannelRead(HANDLE hChannelHandle, WINPR_ATTR_UNUS
 	return TRUE;
 }
 
-BOOL WINAPI FreeRDP_WTSVirtualChannelWrite(HANDLE hChannelHandle, PCHAR Buffer, ULONG Length,
+BOOL WINAPI FreeRDP_WTSVirtualChannelWrite(HANDLE hChannelHandle, PCHAR Buffer, ULONG uLength,
                                            PULONG pBytesWritten)
 {
 	wStream* s = NULL;
@@ -1646,7 +1646,7 @@ BOOL WINAPI FreeRDP_WTSVirtualChannelWrite(HANDLE hChannelHandle, PCHAR Buffer,
 	int cbChId = 0;
 	int first = 0;
 	BYTE* buffer = NULL;
-	UINT32 totalWritten = 0;
+	size_t totalWritten = 0;
 	rdpPeerChannel* channel = (rdpPeerChannel*)hChannelHandle;
 	BOOL ret = FALSE;
 
@@ -1657,8 +1657,7 @@ BOOL WINAPI FreeRDP_WTSVirtualChannelWrite(HANDLE hChannelHandle, PCHAR Buffer,
 	WINPR_ASSERT(channel->vcm);
 	if (channel->channelType == RDP_PEER_CHANNEL_TYPE_SVC)
 	{
-		const ULONG length = Length;
-		buffer = (BYTE*)malloc(length);
+		buffer = (BYTE*)malloc(uLength);
 
 		if (!buffer)
 		{
@@ -1666,9 +1665,9 @@ BOOL WINAPI FreeRDP_WTSVirtualChannelWrite(HANDLE hChannelHandle, PCHAR Buffer,
 			goto fail;
 		}
 
-		CopyMemory(buffer, Buffer, length);
-		totalWritten = Length;
-		if (!wts_queue_send_item(channel, buffer, length))
+		CopyMemory(buffer, Buffer, uLength);
+		totalWritten = uLength;
+		if (!wts_queue_send_item(channel, buffer, uLength))
 			goto fail;
 	}
 	else if (!channel->vcm->drdynvc_channel || (channel->vcm->drdynvc_state != DRDYNVC_STATE_READY))
@@ -1680,6 +1679,7 @@ BOOL WINAPI FreeRDP_WTSVirtualChannelWrite(HANDLE hChannelHandle, PCHAR Buffer,
 	{
 		first = TRUE;
 
+		size_t Length = uLength;
 		while (Length > 0)
 		{
 			s = Stream_New(NULL, DVC_MAX_DATA_PDU_SIZE);
@@ -1697,7 +1697,7 @@ BOOL WINAPI FreeRDP_WTSVirtualChannelWrite(HANDLE hChannelHandle, PCHAR Buffer,
 
 			if (first && (Length > Stream_GetRemainingLength(s)))
 			{
-				cbLen = wts_write_variable_uint(s, Length);
+				cbLen = wts_write_variable_uint(s, WINPR_ASSERTING_INT_CAST(uint32_t, Length));
 				buffer[0] = ((DATA_FIRST_PDU << 4) | (cbLen << 2) | cbChId) & 0xFF;
 			}
 			else
@@ -1725,7 +1725,7 @@ BOOL WINAPI FreeRDP_WTSVirtualChannelWrite(HANDLE hChannelHandle, PCHAR Buffer,
 	}
 
 	if (pBytesWritten)
-		*pBytesWritten = totalWritten;
+		*pBytesWritten = WINPR_ASSERTING_INT_CAST(uint32_t, totalWritten);
 
 	ret = TRUE;
 fail:
diff --git a/libfreerdp/core/transport.c b/libfreerdp/core/transport.c
index e0407b8f8..0773c41dc 100644
--- a/libfreerdp/core/transport.c
+++ b/libfreerdp/core/transport.c
@@ -1225,11 +1225,24 @@ static int transport_default_write(rdpTransport* transport, wStream* s)
 			}
 		}
 
-		length -= (size_t)status;
-		Stream_Seek(s, (size_t)status);
+		const size_t ustatus = (size_t)status;
+		if (ustatus > length)
+		{
+			status = -1;
+			goto out_cleanup;
+		}
+
+		length -= ustatus;
+		Stream_Seek(s, ustatus);
 	}
 
-	transport->written += writtenlength;
+	if (writtenlength + transport->written > UINT32_MAX)
+	{
+		status = -1;
+		goto out_cleanup;
+	}
+
+	transport->written += WINPR_ASSERTING_INT_CAST(uint32_t, writtenlength);
 out_cleanup:
 
 	if (status < 0)
diff --git a/libfreerdp/core/update.c b/libfreerdp/core/update.c
index 1c6c2042d..847626430 100644
--- a/libfreerdp/core/update.c
+++ b/libfreerdp/core/update.c
@@ -2494,7 +2494,7 @@ static BOOL update_send_set_keyboard_ime_status(rdpContext* context, UINT16 imeI
 static UINT16 update_calculate_new_or_existing_window(const WINDOW_ORDER_INFO* orderInfo,
                                                       const WINDOW_STATE_ORDER* stateOrder)
 {
-	UINT16 orderSize = 11;
+	size_t orderSize = 11;
 
 	WINPR_ASSERT(orderInfo);
 	WINPR_ASSERT(stateOrder);
@@ -2539,13 +2539,20 @@ static UINT16 update_calculate_new_or_existing_window(const WINDOW_ORDER_INFO* o
 		orderSize += 8;
 
 	if ((orderInfo->fieldFlags & WINDOW_ORDER_FIELD_WND_RECTS) != 0)
-		orderSize += 2 + stateOrder->numWindowRects * sizeof(RECTANGLE_16);
+	{
+		const size_t len = 2ULL + stateOrder->numWindowRects * sizeof(RECTANGLE_16);
+		orderSize += len;
+	}
 
 	if ((orderInfo->fieldFlags & WINDOW_ORDER_FIELD_VIS_OFFSET) != 0)
 		orderSize += 8;
 
 	if ((orderInfo->fieldFlags & WINDOW_ORDER_FIELD_VISIBILITY) != 0)
-		orderSize += 2 + stateOrder->numVisibilityRects * sizeof(RECTANGLE_16);
+	{
+
+		const size_t len = 2ULL + stateOrder->numVisibilityRects * sizeof(RECTANGLE_16);
+		orderSize += len;
+	}
 
 	if ((orderInfo->fieldFlags & WINDOW_ORDER_FIELD_OVERLAY_DESCRIPTION) != 0)
 		orderSize += 2 + stateOrder->OverlayDescription.length;
@@ -2562,7 +2569,7 @@ static UINT16 update_calculate_new_or_existing_window(const WINDOW_ORDER_INFO* o
 	if ((orderInfo->fieldFlags & WINDOW_ORDER_FIELD_APPBAR_EDGE) != 0)
 		orderSize += 1;
 
-	return orderSize;
+	return WINPR_ASSERTING_INT_CAST(uint16_t, orderSize);
 }
 
 static BOOL update_write_order_field_flags(UINT32 fieldFlags, const WINDOW_STATE_ORDER* stateOrder,
diff --git a/libfreerdp/crypto/crypto.c b/libfreerdp/crypto/crypto.c
index 3cf94cefb..819a4aebc 100644
--- a/libfreerdp/crypto/crypto.c
+++ b/libfreerdp/crypto/crypto.c
@@ -202,7 +202,7 @@ char* crypto_read_pem(const char* WINPR_RESTRICT filename, size_t* WINPR_RESTRIC
 	const int rs = _fseeki64(fp, 0, SEEK_END);
 	if (rs < 0)
 		goto fail;
-	const SSIZE_T size = _ftelli64(fp);
+	const int64_t size = _ftelli64(fp);
 	if (size < 0)
 		goto fail;
 	const int rc = _fseeki64(fp, 0, SEEK_SET);
diff --git a/libfreerdp/locale/keyboard.c b/libfreerdp/locale/keyboard.c
index 29c5ec920..e1964c41d 100644
--- a/libfreerdp/locale/keyboard.c
+++ b/libfreerdp/locale/keyboard.c
@@ -246,7 +246,11 @@ static int freerdp_detect_keyboard(DWORD* keyboardLayoutId)
 	}
 
 	if (*keyboardLayoutId == 0)
-		*keyboardLayoutId = ((DWORD)GetKeyboardLayout(0) >> 16) & 0x0000FFFF;
+	{
+		const HKL layout = GetKeyboardLayout(0);
+		const uint32_t masked = (uint32_t)(((uintptr_t)layout >> 16) & 0xFFFF);
+		*keyboardLayoutId = masked;
+	}
 #endif
 
 #if defined(__MACOSX__)
diff --git a/winpr/libwinpr/sspi/NTLM/ntlm_av_pairs.c b/winpr/libwinpr/sspi/NTLM/ntlm_av_pairs.c
index 300da8abc..ea730f913 100644
--- a/winpr/libwinpr/sspi/NTLM/ntlm_av_pairs.c
+++ b/winpr/libwinpr/sspi/NTLM/ntlm_av_pairs.c
@@ -183,10 +183,10 @@ void ntlm_print_av_pair_list(NTLM_AV_PAIR* pAvPairList, size_t cbAvPairList)
 }
 #endif
 
-static ULONG ntlm_av_pair_list_size(ULONG AvPairsCount, ULONG AvPairsValueLength)
+static size_t ntlm_av_pair_list_size(size_t AvPairsCount, size_t AvPairsValueLength)
 {
 	/* size of headers + value lengths + terminating MsvAvEOL AV_PAIR */
-	return ((AvPairsCount + 1) * 4) + AvPairsValueLength;
+	return ((AvPairsCount + 1) * 4ULL) + AvPairsValueLength;
 }
 
 PBYTE ntlm_av_pair_get_value_pointer(NTLM_AV_PAIR* pAvPair)
@@ -478,7 +478,6 @@ static void ntlm_compute_single_host_data(NTLM_CONTEXT* context)
 BOOL ntlm_construct_challenge_target_info(NTLM_CONTEXT* context)
 {
 	BOOL rc = FALSE;
-	ULONG length = 0;
 	ULONG AvPairsCount = 0;
 	ULONG AvPairsLength = 0;
 	NTLM_AV_PAIR* pAvPairList = NULL;
@@ -511,9 +510,10 @@ BOOL ntlm_construct_challenge_target_info(NTLM_CONTEXT* context)
 	AvPairsCount = 5;
 	AvPairsLength = NbDomainName.Length + NbComputerName.Length + DnsDomainName.Length +
 	                DnsComputerName.Length + 8;
-	length = ntlm_av_pair_list_size(AvPairsCount, AvPairsLength);
+	const size_t length = ntlm_av_pair_list_size(AvPairsCount, AvPairsLength);
 
-	if (!sspi_SecBufferAlloc(&context->ChallengeTargetInfo, length))
+	if (!sspi_SecBufferAlloc(&context->ChallengeTargetInfo,
+	                         WINPR_ASSERTING_INT_CAST(uint32_t, length)))
 		goto fail;
 
 	pAvPairList = (NTLM_AV_PAIR*)context->ChallengeTargetInfo.pvBuffer;
@@ -553,7 +553,6 @@ fail:
 
 BOOL ntlm_construct_authenticate_target_info(NTLM_CONTEXT* context)
 {
-	ULONG size = 0;
 	ULONG AvPairsCount = 0;
 	ULONG AvPairsValueLength = 0;
 	NTLM_AV_PAIR* AvTimestamp = NULL;
@@ -675,12 +674,13 @@ BOOL ntlm_construct_authenticate_target_info(NTLM_CONTEXT* context)
 		}
 	}
 
-	size = ntlm_av_pair_list_size(AvPairsCount, AvPairsValueLength);
+	size_t size = ntlm_av_pair_list_size(AvPairsCount, AvPairsValueLength);
 
 	if (context->NTLMv2)
 		size += 8; /* unknown 8-byte padding */
 
-	if (!sspi_SecBufferAlloc(&context->AuthenticateTargetInfo, size))
+	if (!sspi_SecBufferAlloc(&context->AuthenticateTargetInfo,
+	                         WINPR_ASSERTING_INT_CAST(uint32_t, size)))
 		goto fail;
 
 	AuthenticateTargetInfo = (NTLM_AV_PAIR*)context->AuthenticateTargetInfo.pvBuffer;
diff --git a/winpr/libwinpr/utils/windows/debug.c b/winpr/libwinpr/utils/windows/debug.c
index 84e04c2cd..7790d0af2 100644
--- a/winpr/libwinpr/utils/windows/debug.c
+++ b/winpr/libwinpr/utils/windows/debug.c
@@ -130,7 +130,6 @@ char** winpr_win_backtrace_symbols(void* buffer, size_t* used)
 
 char* winpr_win_strerror(DWORD dw, char* dmsg, size_t size)
 {
-	DWORD rc;
 	DWORD nSize = 0;
 	DWORD dwFlags = 0;
 	LPTSTR msg = NULL;
@@ -143,12 +142,12 @@ char* winpr_win_strerror(DWORD dw, char* dmsg, size_t size)
 	nSize = (DWORD)(size * sizeof(WCHAR));
 	msg = (LPTSTR)calloc(nSize, sizeof(WCHAR));
 #endif
-	rc = FormatMessage(dwFlags, NULL, dw, 0, alloc ? (LPTSTR)&msg : msg, nSize, NULL);
+	const DWORD rc = FormatMessage(dwFlags, NULL, dw, 0, alloc ? (LPTSTR)&msg : msg, nSize, NULL);
 
-	if (rc)
+	if (rc > 0)
 	{
 #if defined(UNICODE)
-		WideCharToMultiByte(CP_ACP, 0, msg, rc, dmsg, (int)MIN(size - 1, INT_MAX), NULL, NULL);
+		WideCharToMultiByte(CP_ACP, 0, msg, (int)rc, dmsg, (int)MIN(size - 1, INT_MAX), NULL, NULL);
 #else  /* defined(UNICODE) */
 		memcpy(dmsg, msg, MIN(rc, size - 1));
 #endif /* defined(UNICODE) */