diff --git a/toonz/sources/toonz/previewfxmanager.cpp b/toonz/sources/toonz/previewfxmanager.cpp
index e8df158..82b61b0 100644
--- a/toonz/sources/toonz/previewfxmanager.cpp
+++ b/toonz/sources/toonz/previewfxmanager.cpp
@@ -1079,7 +1079,7 @@ void PreviewFxInstance::doOnRenderRasterCompleted(
 
   /*-- 16bpcで計算された場合、結果をDitheringする --*/
   // dither the 16bpc image IF the "30bit display" preference option is OFF
-  if ((rasA->getPixelSize() == 8 || rasA->getPixelSize() == 16) &&
+  if (rasA->getPixelSize() == 8 &&
       !Preferences::instance()->is30bitDisplayEnabled())  // render in 64 bits
   {
     TRaster32P auxA(rasA->getLx(), rasA->getLy());