diff --git a/CHANGELOG.md b/CHANGELOG.md
index 2745fb0..e1435f8 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -10,7 +10,7 @@
 * promise: new API module
 * errors: finish normalisation of all errors
 
-## Trunk
+## Version 4.10.1
 
 Minor improvements:
 * columns_duplicates_to_array: error and type
diff --git a/lib/es5/index.d.ts b/lib/es5/index.d.ts
index 00f45b4..7a2491e 100644
--- a/lib/es5/index.d.ts
+++ b/lib/es5/index.d.ts
@@ -77,6 +77,11 @@ declare namespace parse {
          * affect the result data set in the sense that records will be objects instead of arrays.
          */
         columns?: ColumnOption[] | boolean | ((record: any) => ColumnOption[]);
+        /**
+         * Convert values into an array of values when columns are activated and
+         * when multiple columns of the same name are found.
+         */
+        columns_duplicates_to_array?: boolean;
         /**
          * Treat all the characters after this one as a comment, default to '' (disabled).
          */
diff --git a/package.json b/package.json
index ef77ed3..57e3f47 100644
--- a/package.json
+++ b/package.json
@@ -1,5 +1,5 @@
 {
-  "version": "4.10.0",
+  "version": "4.10.1",
   "name": "csv-parse",
   "description": "CSV parsing implementing the Node.js `stream.Transform` API",
   "keywords": [