diff --git a/src/ontology/uberon-edit.obo b/src/ontology/uberon-edit.obo
index dcd97f9373..1f2bca9482 100644
--- a/src/ontology/uberon-edit.obo
+++ b/src/ontology/uberon-edit.obo
@@ -8749,6 +8749,7 @@ xref: VHOG:0000098
 xref: Wikipedia:Endocrine_system
 xref: XAO:0000158
 xref: ZFA:0001158
+is_a: UBERON:0015203 ! non-connected functional system
 disjoint_from: UBERON:0000990 ! reproductive system
 disjoint_from: UBERON:0001004 ! respiratory system
 disjoint_from: UBERON:0001007 ! digestive system