diff --git a/lib/isc/lex.c b/lib/isc/lex.c
index ad14dc7e70..83833b9ed7 100644
--- a/lib/isc/lex.c
+++ b/lib/isc/lex.c
@@ -133,8 +133,8 @@ isc_lex_destroy(isc_lex_t **lexp) {
 		isc_lex_close(lex);
 	if (lex->data != NULL)
 		isc_mem_put(lex->mctx, lex->data, lex->max_token + 1);
-	isc_mem_put(lex->mctx, lex, sizeof *lex);
 	lex->magic = 0;
+	isc_mem_put(lex->mctx, lex, sizeof *lex);
 
 	*lexp = NULL;
 }