diff --git a/README.md b/README.md
index 01909bb..62a201d 100644
--- a/README.md
+++ b/README.md
@@ -246,6 +246,14 @@ Functions have a precedence of 190.
 
 ### [Serde](https://serde.rs)
 
+To use this crate with serde, the serde feature flag has to be set.
+This can be done like this in the `Cargo.toml`:
+
+```toml
+[dependencies]
+evalexpr = {version = "1", features = ["serde"]}
+```
+
 This crate implements `serde::de::Deserialize` for its type `Node` that represents a parsed expression tree.
 The implementation expects a [serde `string`](https://serde.rs/data-model.html) as input.
 Example parsing with [ron format](docs.rs/ron):
diff --git a/src/lib.rs b/src/lib.rs
index f42379a..87aee07 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -233,6 +233,14 @@
 //!
 //! ### [Serde](https://serde.rs)
 //!
+//! To use this crate with serde, the serde feature flag has to be set.
+//! This can be done like this in the `Cargo.toml`:
+//!
+//! ```toml
+//! [dependencies]
+//! evalexpr = {version = "1", features = ["serde"]}
+//! ```
+//!
 //! This crate implements `serde::de::Deserialize` for its type `Node` that represents a parsed expression tree.
 //! The implementation expects a [serde `string`](https://serde.rs/data-model.html) as input.
 //! Example parsing with [ron format](docs.rs/ron):