diff --git a/README.md b/README.md
index 804fae9d7bd..40c42db6111 100644
--- a/README.md
+++ b/README.md
@@ -103,6 +103,8 @@ $ python
 '25'
 ```
 
+When checking runtime performance, run `maturin develop --release` to build with optimizations.
+
 To make changes to the package, just edit the Rust source code and then re-run `maturin develop` to recompile.
 
 To run this all as a single copy-and-paste, use the bash script below (replace `string_sum` in the first command with the desired package name):
diff --git a/guide/src/getting-started.md b/guide/src/getting-started.md
index b7d6fb98046..f8b1d768842 100644
--- a/guide/src/getting-started.md
+++ b/guide/src/getting-started.md
@@ -192,6 +192,9 @@ $ python
 '25'
 ```
 
+By default, `maturin develop` builds your Rust code with Cargo's default [`dev` profile](https://doc.rust-lang.org/cargo/reference/profiles.html#default-profiles), which includes debug information and limited optimizations.
+When checking runtime performance, run `maturin develop --release` to build with Cargo's `release` profile and enable optimizations.
+
 For more instructions on how to use Python code from Rust, see the [Python from Rust](python-from-rust.md) page.
 
 ## Maturin Import Hook