diff --git a/Cargo.toml b/Cargo.toml
index 20daf2a..d644ebc 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -13,6 +13,9 @@ homepage = "https://github.com/enarx/flagset"
 documentation = "https://docs.rs/flagset"
 description = "Data types and a macro for generating enumeration-based bit flags"
 
+[features]
+std = []
+
 [dependencies.serde]
 version = "1.0"
 optional = true
@@ -26,3 +29,4 @@ version = "0.1"
 
 [package.metadata.docs.rs]
 all-features = true
+rustdoc-args = ["--cfg", "docsrs"]
diff --git a/src/lib.rs b/src/lib.rs
index c44b04b..273f238 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -245,7 +245,8 @@ appropriate `repr` attribute:
 )]
 #![allow(unknown_lints)]
 #![warn(clippy::all)]
-#![no_std]
+#![cfg_attr(not(feature = "std"), no_std)]
+#![cfg_attr(docsrs, feature(doc_auto_cfg))]
 
 use core::fmt::{Debug, Formatter, Result};
 use core::ops::*;
@@ -276,6 +277,9 @@ impl core::fmt::Display for InvalidBits {
     }
 }
 
+#[cfg(feature = "std")]
+impl std::error::Error for InvalidBits {}
+
 #[doc(hidden)]
 pub trait Flags:
     Copy