diff --git a/share/completions/function.fish b/share/completions/function.fish
index aa2d6643b..3620c07bd 100644
--- a/share/completions/function.fish
+++ b/share/completions/function.fish
@@ -6,3 +6,4 @@ complete -c function -s p -l on-process-exit --description "Make the function a
 complete -c function -s s -l on-signal --description "Make the function a signal event handler" -x
 complete -c function -s v -l on-variable --description "Make the function a variable update event handler" -x
 complete -c function -s b -l key-binding --description "Allow dash (-) in function name"
+complete -c function -s a -l argument-names --description "Specify named arguments"