diff --git a/lib/dns/rdata/generic/mx_15.c b/lib/dns/rdata/generic/mx_15.c
index fd09e92535..bec8e4923c 100644
--- a/lib/dns/rdata/generic/mx_15.c
+++ b/lib/dns/rdata/generic/mx_15.c
@@ -57,7 +57,6 @@ fromtext_mx(ARGS_FROMTEXT) {
 
 	UNUSED(type);
 	UNUSED(rdclass);
-	UNUSED(callbacks);
 
 	RETERR(isc_lex_getmastertoken(lexer, &token, isc_tokentype_number,
 				      ISC_FALSE));