diff --git a/source/Lib/DecoderLib/CABACReader.cpp b/source/Lib/DecoderLib/CABACReader.cpp
index b08e7f32d460ba9ffdff0d2088e0bcb7cba0cd95..0f7937f98dba31e10c12853ea6029b3cc293d36c 100644
--- a/source/Lib/DecoderLib/CABACReader.cpp
+++ b/source/Lib/DecoderLib/CABACReader.cpp
@@ -3502,7 +3502,7 @@ void CABACReader::explicit_rdpcm_mode( TransformUnit& tu, ComponentID compID )
 
 void CABACReader::residual_lfnst_mode( CodingUnit& cu,  CUCtx& cuCtx  )
 {
-  int chIdx = CS::isDualITree( *cu.cs ) && cu.chType == CHANNEL_TYPE_CHROMA ? 1 : 0;
+  int chIdx = cu.isSepTree() && cu.chType == CHANNEL_TYPE_CHROMA ? 1 : 0;
 #if JVET_P1026_ISP_LFNST_COMBINATION
   if ( (cu.ispMode && !CU::canUseLfnstWithISP( cu, cu.chType ) ) ||
 #else
diff --git a/source/Lib/EncoderLib/CABACWriter.cpp b/source/Lib/EncoderLib/CABACWriter.cpp
index 81b30591af61954791612c172b48431f0ec86180..7c3344497bf17b3c415cc7579f51e900cc179d35 100644
--- a/source/Lib/EncoderLib/CABACWriter.cpp
+++ b/source/Lib/EncoderLib/CABACWriter.cpp
@@ -3196,7 +3196,7 @@ void CABACWriter::explicit_rdpcm_mode( const TransformUnit& tu, ComponentID comp
 
 void CABACWriter::residual_lfnst_mode( const CodingUnit& cu, CUCtx& cuCtx )
 {
-  int chIdx = CS::isDualITree( *cu.cs ) && cu.chType == CHANNEL_TYPE_CHROMA ? 1 : 0;
+  int chIdx = cu.isSepTree() && cu.chType == CHANNEL_TYPE_CHROMA ? 1 : 0;
 #if JVET_P1026_ISP_LFNST_COMBINATION
   if( ( cu.ispMode && !CU::canUseLfnstWithISP( cu, cu.chType ) ) ||
 #else