diff --git a/builtin_complete.c b/builtin_complete.c
index 18f85c4ab..0b7eede63 100644
--- a/builtin_complete.c
+++ b/builtin_complete.c
@@ -364,7 +364,7 @@ static int builtin_complete( wchar_t **argv )
 				}
 				,
 				{
-					L"do-complete", required_argument, 0, 'C'
+					L"do-complete", optional_argument, 0, 'C'
 				}
 				,
 				{