diff --git a/src/ontology/go-edit.obo b/src/ontology/go-edit.obo
index 4db387c6d0..6a8d6c383a 100644
--- a/src/ontology/go-edit.obo
+++ b/src/ontology/go-edit.obo
@@ -16809,7 +16809,7 @@ relationship: part_of GO:0002381 ! immunoglobulin production involved in immunog
 id: GO:0002209
 name: behavioral defense response
 namespace: biological_process
-def: "A behavioral response seeking to protect an organism from an a perceived external threat to that organism." [GO_REF:0000022, GOC:add]
+def: "A behavioral response seeking to protect an organism from an perceived external threat to that organism." [GO_REF:0000022, GOC:add]
 synonym: "behavioural defense response" EXACT []
 is_a: GO:0006952 ! defense response
 is_a: GO:0007610 ! behavior