diff --git a/toonz/sources/common/tstream/tstream.cpp b/toonz/sources/common/tstream/tstream.cpp
index d677eae..ac70b7f 100644
--- a/toonz/sources/common/tstream/tstream.cpp
+++ b/toonz/sources/common/tstream/tstream.cpp
@@ -260,7 +260,7 @@ TOStream::TOStream(const TFilePath &fp, bool compressed)
 TOStream::TOStream(std::shared_ptr<Imp> imp)
 	: m_imp(std::move(imp))
 {
-	assert(!imp->m_tagStack.empty());
+	assert(!m_imp->m_tagStack.empty());
 	ostream &os = *m_imp->m_os;
 	if (m_imp->m_justStarted == false)
 		cr();
diff --git a/toonz/sources/toonzlib/convert2tlv.cpp b/toonz/sources/toonzlib/convert2tlv.cpp
index 9755dcc..25b9758 100644
--- a/toonz/sources/toonzlib/convert2tlv.cpp
+++ b/toonz/sources/toonzlib/convert2tlv.cpp
@@ -344,8 +344,8 @@ void Convert2Tlv::buildInksForNAAImage(TRasterCM32P &rout, const TRaster32P &rin
 		for (j = 0; j < rin->getLx(); j++, pixin++, pixout++) {
 			TPixel colorIn;
 
-			/*-白ピクセルを透明として扱う-*/
-			if (*pixin == TPixel(255, 255, 255)) {
+			/*- treat white/transparent pixels as transparent -*/
+			if (*pixin == TPixel(255, 255, 255) || *pixin == TPixel::Transparent) {
 				*pixout = TPixelCM32(0, 0, 255);
 				continue;
 			}