diff --git a/analyzer/asn1.spicy b/analyzer/asn1.spicy
index d0a417f..24f35f9 100644
--- a/analyzer/asn1.spicy
+++ b/analyzer/asn1.spicy
@@ -92,7 +92,8 @@ type ASN1Tag = unit {
   var class: ASN1Class;
   var constructed: bool;
 
-  : bitfield(8) {
+  # TODO(bbannier): Use an anonymous bitfield here once zeek/spicy#1533 is fixed.
+  bits: bitfield(8) {
     num: 0..4;
     constructed: 5;
     class: 6..7;