diff --git a/lib/fromPgn.js b/lib/fromPgn.js
index 5fa522d..5ccd15a 100644
--- a/lib/fromPgn.js
+++ b/lib/fromPgn.js
@@ -611,6 +611,7 @@ function readField(options, runPostProcessor, pgn, field, bs, fields) {
       }
       if ( options.checkForInvalidFields !== false && max !== 'undefined' &&
            field.FieldType !== 'LOOKUP' &&
+           field.FieldType !== 'FIELDTYPE_LOOKUP' &&
            field.BitLength > 1 &&
            max - value <= 0 ) {
         //console.log(`Bad field ${field.Name} ${max - value}`)
@@ -633,7 +634,8 @@ function readField(options, runPostProcessor, pgn, field, bs, fields) {
         value = Number.parseFloat(value.toFixed(precision))
       }
 
-      if (field.FieldType === 'LOOKUP' &&
+      if ((field.FieldType === 'LOOKUP' ||
+           field.FieldType === 'FIELDTYPE_LOOKUP') &&
           runPostProcessor &&
           (_.isUndefined(options.resolveEnums) ||
            options.resolveEnums)) {
diff --git a/lib/toPgn.js b/lib/toPgn.js
index 6335168..f5f0fc9 100644
--- a/lib/toPgn.js
+++ b/lib/toPgn.js
@@ -190,7 +190,8 @@ function writeField(bs, pgn_number, field, data, value, fields, bitLength) {
       }
     } else if ( type && fieldTypeMappers[type] ) {
       value = fieldTypeMappers[type](field, value)
-    } else if (field.FieldType === 'LOOKUP' && _.isString(value)) {
+    } else if ((field.FieldType === 'LOOKUP' ||
+                field.FieldType === 'FIELDTYPE_LOOKUP') && _.isString(value)) {
       if (!(field.Id === "timeStamp" && value < 60)) {
         value = lookup(field, value)
       }