diff --git a/lib/libc/stdlib/getopt.3 b/lib/libc/stdlib/getopt.3
index 161492437189..d8beee2e2b34 100644
--- a/lib/libc/stdlib/getopt.3
+++ b/lib/libc/stdlib/getopt.3
@@ -142,7 +142,7 @@ returns \-1.
 If the
 .Fn getopt
 function encounters a character not found in the string
-.Va optarg
+.Va optstring
 or detects
 a missing option argument it writes an error message to the
 .Em stderr