diff --git a/libs/clipboard/src/windows/wf_cliprdr.c b/libs/clipboard/src/windows/wf_cliprdr.c
index c32a20259..3baf83a1d 100644
--- a/libs/clipboard/src/windows/wf_cliprdr.c
+++ b/libs/clipboard/src/windows/wf_cliprdr.c
@@ -2443,9 +2443,6 @@ static FILEDESCRIPTORW *wf_cliprdr_get_file_descriptor(WCHAR *file_name, size_t
 		return NULL;
 	}
 
-	// to-do: use `fd->dwFlags = FD_ATTRIBUTES | FD_FILESIZE | FD_WRITESTIME | FD_PROGRESSUI`.
-	// We keep `fd->dwFlags = FD_ATTRIBUTES | FD_WRITESTIME | FD_PROGRESSUI` for compatibility.
-	// fd->dwFlags = FD_ATTRIBUTES | FD_FILESIZE | FD_WRITESTIME | FD_PROGRESSUI;
 	fd->dwFlags = FD_ATTRIBUTES | FD_WRITESTIME | FD_PROGRESSUI;
 	fd->dwFileAttributes = GetFileAttributesW(file_name);
 	if (fd->dwFileAttributes == INVALID_FILE_ATTRIBUTES)
@@ -2458,7 +2455,34 @@ static FILEDESCRIPTORW *wf_cliprdr_get_file_descriptor(WCHAR *file_name, size_t
 		fd->dwFlags &= ~FD_WRITESTIME;
 	}
 
-	fd->nFileSizeLow = GetFileSize(hFile, &fd->nFileSizeHigh);
+	// Announce the size in the file list. Without FD_FILESIZE the receiving side cannot
+	// trust the size fields, so CliprdrStream_New() asks for each file's size with its own
+	// FILECONTENTS_SIZE request and blocks on the reply. Those requests are made for every
+	// entry up front, while the shell is inside IDataObject::GetData(), so the cost grows
+	// with the number of files and not with their size.
+	//
+	// GetFileSize() reports failure as INVALID_FILE_SIZE, which cannot be told apart from a
+	// genuine 4GB-1 file without GetLastError(), and it fails outright on the directory
+	// handles FILE_FLAG_BACKUP_SEMANTICS lets us open above. A directory gets no size. A
+	// file whose size cannot be read is rejected rather than sent with the flag off: the
+	// Unix receiver reads the size fields whether or not the flag is set, for compatibility
+	// with older Windows senders, and would take the zero for an empty file.
+	if ((fd->dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY) == 0)
+	{
+		LARGE_INTEGER file_size = {0};
+
+		if (!GetFileSizeEx(hFile, &file_size) || file_size.QuadPart < 0)
+		{
+			CloseHandle(hFile);
+			free(fd);
+			return NULL;
+		}
+
+		fd->nFileSizeLow = file_size.LowPart;
+		fd->nFileSizeHigh = (DWORD)file_size.HighPart;
+		fd->dwFlags |= FD_FILESIZE;
+	}
+
 	if ((wcslen(file_name + pathLen) + 1) > sizeof(fd->cFileName) / sizeof(fd->cFileName[0]))
 	{
 		// The file name is too long, which is not a normal case.