diff --git a/dist/util.d.ts.map b/dist/util.d.ts.map
index 876e5eb..159e9ae 100644
--- a/dist/util.d.ts.map
+++ b/dist/util.d.ts.map
@@ -1 +1 @@
-{"version":3,"file":"util.d.ts","sourceRoot":"","sources":["../src/util.ts"],"names":[],"mappings":"AAWA,wBAAgB,OAAO,CAAC,MAAM,EAAE,GAAG,EAAE,IAAI,GAAE,GAAQ,GAAG,GAAG,EAAE,CAuC1D"}
\ No newline at end of file
+{"version":3,"file":"util.d.ts","sourceRoot":"","sources":["../src/util.ts"],"names":[],"mappings":"AAaA,wBAAgB,OAAO,CAAC,MAAM,EAAE,GAAG,EAAE,IAAI,GAAE,GAAQ,GAAG,GAAG,EAAE,CA0C1D"}
\ No newline at end of file
diff --git a/dist/util.js b/dist/util.js
index 91bc79e..fdeabb1 100644
--- a/dist/util.js
+++ b/dist/util.js
@@ -15,7 +15,10 @@ export function flatten(target, opts = {}) {
     const output = [];
     function step(object, prev, currentDepth) {
         currentDepth = currentDepth || 1;
-        Object.keys(object).forEach(function (key) {
+        if (!Array.isArray(object)) {
+            object = Object.keys(object);
+        }
+        object.forEach(function (key) {
             const value = object[key];
             const isarray = opts.safe && Array.isArray(value);
             const type = Object.prototype.toString.call(value);