diff --git a/primitives/src/lib.rs b/primitives/src/lib.rs
index e8617dea6..b04d624da 100644
--- a/primitives/src/lib.rs
+++ b/primitives/src/lib.rs
@@ -4,7 +4,8 @@
 //!
 //! Primitive data types that are used throughout the [`rust-bitcoin`] ecosystem.
 //!
-//! This crate can be used in a no-std environment but requires an allocator.
+//! This crate can be used in a no-std environment but a lot of the functionality requires an
+//! allocator i.e., requires the `alloc` feature to be enabled.
 //!
 //! [`rust-bitcoin`]: <https://github.com/rust-bitcoin>