diff --git a/index.js b/index.js
index f1877e0..7f4c0e1 100644
--- a/index.js
+++ b/index.js
@@ -1,4 +1,4 @@
 export default function arrayDiffer(array, ...values) {
-	const rest = new Set([...values].flat());
+	const rest = new Set(values.flat());
 	return array.filter(element => !rest.has(element));
 }
diff --git a/readme.md b/readme.md
index d0c8ff4..c8e91fb 100644
--- a/readme.md
+++ b/readme.md
@@ -33,6 +33,12 @@ Type: `unknown[]`
 
 Arrays of values to exclude.
 
+## FAQ
+
+### What is the time complexity of the algorithm?
+
+[Read here.](https://github.com/sindresorhus/array-differ/issues/10)
+
 ---
 
 <div align="center">