diff --git a/document-generator/Tools/DOF_mkroot b/document-generator/Tools/DOF_mkroot
index 2791fed7..4cbd7836 100755
--- a/document-generator/Tools/DOF_mkroot
+++ b/document-generator/Tools/DOF_mkroot
@@ -143,7 +143,7 @@ if [ "$DOC" = true ]; then
   cp "$ISABELLE_HOME_USER/DOF/document-template/preamble.tex" "$DIR"/document/
   cp "$ISABELLE_HOME_USER/DOF/document-template/ontologies.tex" "$DIR"/document/
   for o in $ONTOLOGY; do
-    echo "\usepackage{$o}" >> "$DIR"/document/ontologies.tex;
+    echo "\usepackage{DOF-$o}" >> "$DIR"/document/ontologies.tex;
   done
   sed -e "s/<AUTHOR>/$AUTHOR/" -e "s/<TITLE>/$TITLE/" "$ISABELLE_HOME_USER/DOF/document-template/root-$TEMPLATE.tex" > "$DIR"/document/root.tex
 else