diff --git a/src/graphics/PreviewLoader.cpp b/src/graphics/PreviewLoader.cpp
index 10eeee321d..b4d78e0ab5 100644
--- a/src/graphics/PreviewLoader.cpp
+++ b/src/graphics/PreviewLoader.cpp
@@ -718,6 +718,7 @@ void PreviewLoader::Impl::dumpPreamble(otexstream & os) const
 	runparams.nice = true;
 	runparams.moving_arg = true;
 	runparams.free_spacing = true;
+	runparams.is_child = buffer_.parent();
 	buffer_.writeLaTeXSource(os, buffer_.filePath(), runparams, Buffer::OnlyPreamble);
 
 	// FIXME! This is a HACK! The proper fix is to control the 'true'