diff --git a/twain/ds/scanned_img.cpp b/twain/ds/scanned_img.cpp
index 43481f4..1f0357a 100644
--- a/twain/ds/scanned_img.cpp
+++ b/twain/ds/scanned_img.cpp
@@ -379,7 +379,7 @@ void scanned_img::do_result(twain_xfer xfer)
 						char* mem = new char[size];
 						fread(mem, 1, size, src);
 						fclose(src);
-						data_->save(mem, &size, 0);
+						data_->save(mem, (size_t*)&size, 0);
 						delete[] mem;
 
 						head_.format = SANE_FRAME_GRAY;
@@ -395,7 +395,7 @@ void scanned_img::do_result(twain_xfer xfer)
 					data_ = new image_buf();
 					size = conv.dst.data_len;
 					data_->allocate(file_.c_str(), conv.dst.data_len);
-					data_->save(conv.dst.data, &size, 0);
+					data_->save(conv.dst.data, (size_t*)&size, 0);
 					sane_helper_->invoke_sane_control_option(dev_, SANE_OPT_ID_FREE_BUFFER, SANE_ACTION_SET_VALUE, (void*)&conv.dst.data, &after);
 
 					head_.format = SANE_FRAME_GRAY;