diff --git a/ivl.def b/ivl.def
index 311569ce5..d85e2189d 100644
--- a/ivl.def
+++ b/ivl.def
@@ -18,6 +18,7 @@ ivl_const_bits
 ivl_const_delay
 ivl_const_file
 ivl_const_lineno
+ivl_const_nex
 ivl_const_real
 ivl_const_scope
 ivl_const_signed