diff --git a/subsets/Makefile b/subsets/Makefile
index 181d2ed..882b453 100644
--- a/subsets/Makefile
+++ b/subsets/Makefile
@@ -13,7 +13,10 @@ taxslim: taxon-subset-ids.txt
 	robot convert -i taxslim.owl -f json -o taxslim.json
 
 taxslim-disjoint-over-in-taxon.owl: taxslim
-	owltools taxslim.owl --create-taxon-disjoint-over-in-taxon --root NCBITaxon:1
+	owltools taxslim.owl --create-taxon-disjoint-over-in-taxon --root NCBITaxon:1 --output $@.tmp.owl
+	robot query --input taxslim.owl --format ttl --query add-taxon-disjoints.ru $@.tmp.ttl
+	robot merge --input $@.tmp.owl --input $@.tmp.ttl --output $@
+	rm $@.tmp.owl && rm $@.tmp.ttl
 
 ## The following should not be run as part of CI job.
 ## Admin for this project should run and check in results.
diff --git a/subsets/add-taxon-disjoints.ru b/subsets/add-taxon-disjoints.ru
new file mode 100644
index 0000000..556286e
--- /dev/null
+++ b/subsets/add-taxon-disjoints.ru
@@ -0,0 +1,22 @@
+PREFIX rdfs: <http://www.w3.org/2000/01/rdf-schema#>
+PREFIX rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#>
+PREFIX owl: <http://www.w3.org/2002/07/owl#>
+PREFIX in_taxon: <http://purl.obolibrary.org/obo/RO_0002162>
+CONSTRUCT {
+  [  
+     a owl:Restriction ;
+     owl:onProperty in_taxon: ;
+     owl:someValuesFrom ?subtaxon ;
+     owl:disjointWith [
+       a owl:Restriction ;
+       owl:onProperty in_taxon: ;
+       owl:someValuesFrom [
+         a owl:Class ;
+         owl:complementOf ?subtaxon
+       ] 
+     ]
+  ] .
+}
+WHERE {
+  ?subtaxon rdf:type owl:Class .
+}