diff --git a/opter.js b/opter.js
index 692ae51..5cdc353 100644
--- a/opter.js
+++ b/opter.js
@@ -40,7 +40,9 @@ module.exports = class Opter {
   parse(argv) {
     this.userOptions = argvToObject(argv);
 
-    // collect user opts with the long names as keys, for output
+    /** 
+     * @type {Object<string, boolean | Array<string>>}
+     * The user-provided with ther long names as the keys **/
     let normalizedUserOptions = {};
 
     Object.keys(this.definedOptions).forEach(longName => {
@@ -128,6 +130,7 @@ function argvToObject(argv) {
     return;
   });
 
+  /** @type {Object<string, boolean | Array<string>>} **/
   let out = {};
   grouped.forEach((a, i) => {
     let next = grouped[i+1];