diff --git a/Cargo.toml b/Cargo.toml
index d2ac2c4..6b7fa0a 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "loop"
-version = "0.2.0"
+version = "0.3.0"
 edition = "2021"
 license = "Apache-2.0/MIT"
 authors = ["Ivan Ukhov <ivan.ukhov@gmail.com>"]
diff --git a/README.md b/README.md
index 806c6b7..4643ea2 100644
--- a/README.md
+++ b/README.md
@@ -2,18 +2,22 @@
 
 The package allows for processing iterators in parallel.
 
-# Example
+# Examples
+
+Synchronously:
 
 ```rust
 let double = |value| 2 * value;
 let _ = r#loop::parallelize(0..10, double, None).collect::<Vec<_>>();
 ```
 
+Asynchronously:
+
 ```rust
 use futures::stream::StreamExt;
 
 let double = |value| async move { 2 * value };
-let _ = r#loop::parallelize(0..10, double, None).collect::<Vec<_>>().await;
+let _ = r#loop::parallelize(0..10, double).collect::<Vec<_>>().await;
 ```
 
 ## Contribution
diff --git a/src/asynchronous.rs b/src/asynchronous.rs
index 0a84262..eb3ce0d 100644
--- a/src/asynchronous.rs
+++ b/src/asynchronous.rs
@@ -7,7 +7,6 @@ use tokio_stream::wrappers::ReceiverStream;
 pub fn parallelize<Items, Item, Map, Future, Output>(
     items: Items,
     mut map: Map,
-    workers: Option<usize>,
 ) -> impl futures::stream::Stream<Item = Output>
 where
     Items: IntoIterator<Item = Item> + Send + 'static,
@@ -17,7 +16,7 @@ where
     Future: std::future::Future<Output = Output> + Send,
     Output: Send + 'static,
 {
-    let workers = crate::support::workers(workers);
+    let workers = crate::support::workers();
     let (item_sender, item_receiver) = mpsc::channel::<Item>(workers);
     let (output_sender, output_receiver) = mpsc::channel::<Output>(workers);
     let item_receiver = Arc::new(Mutex::new(item_receiver));
@@ -48,9 +47,7 @@ mod tests {
 
     #[tokio::test]
     async fn parallelize() {
-        let mut values = super::parallelize(0..10, double, None)
-            .collect::<Vec<_>>()
-            .await;
+        let mut values = super::parallelize(0..10, double).collect::<Vec<_>>().await;
         values.sort();
         assert_eq!(values, &[0, 2, 4, 6, 8, 10, 12, 14, 16, 18]);
     }
diff --git a/src/lib.rs b/src/lib.rs
index 4fa96f9..8d38285 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -1,25 +1,29 @@
 //! Processing iterators in parallel.
 //!
-//! # Example
+//! # Examples
+//!
+//! Synchronously:
 //!
 //! ```
 //! # #[cfg(not(feature = "asynchronous"))]
 //! fn main() {
-//!     let multiply = |value| 2 * value;
-//!     let _ = r#loop::parallelize(0..10, multiply, None).collect::<Vec<_>>();
+//!     let double = |value| 2 * value;
+//!     let _ = r#loop::parallelize(0..10, double).collect::<Vec<_>>();
 //! }
 //! # #[cfg(feature = "asynchronous")]
 //! # fn main() {}
 //!```
 //!
+//! Asynchronously:
+//!
 //!```
 //! # #[cfg(feature = "asynchronous")]
 //! #[tokio::main]
 //! async fn main() {
 //!     use futures::stream::StreamExt;
 //!
-//!     let multiply = |value| async move { 2 * value };
-//!     let _ = r#loop::parallelize(0..10, multiply, None).collect::<Vec<_>>().await;
+//!     let double = |value| async move { 2 * value };
+//!     let _ = r#loop::parallelize(0..10, double).collect::<Vec<_>>().await;
 //! }
 //! # #[cfg(not(feature = "asynchronous"))]
 //! # fn main() {}
diff --git a/src/support.rs b/src/support.rs
index 2673225..7354c8a 100644
--- a/src/support.rs
+++ b/src/support.rs
@@ -1,7 +1,5 @@
-pub fn workers(value: Option<usize>) -> usize {
-    value.unwrap_or_else(|| {
-        std::thread::available_parallelism()
-            .map(|value| value.get())
-            .unwrap_or(1)
-    })
+pub fn workers() -> usize {
+    std::thread::available_parallelism()
+        .map(|value| value.get())
+        .unwrap_or(1)
 }
diff --git a/src/synchronous.rs b/src/synchronous.rs
index 912638f..4d6b19c 100644
--- a/src/synchronous.rs
+++ b/src/synchronous.rs
@@ -4,7 +4,6 @@ use std::sync::{mpsc, Arc, Mutex};
 pub fn parallelize<Items, Item, Map, Output>(
     items: Items,
     mut map: Map,
-    workers: Option<usize>,
 ) -> impl Iterator<Item = Output>
 where
     Items: IntoIterator<Item = Item> + Send + 'static,
@@ -12,7 +11,7 @@ where
     Map: FnMut(Item) -> Output + Copy + Send + 'static,
     Output: Send + 'static,
 {
-    let workers = crate::support::workers(workers);
+    let workers = crate::support::workers();
     let (item_sender, item_receiver) = mpsc::sync_channel::<Item>(workers);
     let (output_sender, output_receiver) = mpsc::sync_channel::<Output>(workers);
     let item_receiver = Arc::new(Mutex::new(item_receiver));
@@ -41,7 +40,7 @@ where
 mod tests {
     #[test]
     fn parallelize() {
-        let mut values = super::parallelize(0..10, double, None).collect::<Vec<_>>();
+        let mut values = super::parallelize(0..10, double).collect::<Vec<_>>();
         values.sort();
         assert_eq!(values, &[0, 2, 4, 6, 8, 10, 12, 14, 16, 18]);
     }