diff --git a/crates/matrix-sdk-crypto/Cargo.toml b/crates/matrix-sdk-crypto/Cargo.toml
index 3635ba628..5e31b4945 100644
--- a/crates/matrix-sdk-crypto/Cargo.toml
+++ b/crates/matrix-sdk-crypto/Cargo.toml
@@ -15,6 +15,9 @@ version = "0.4.1"
 features = ["docsrs"]
 rustdoc-args = ["--cfg", "docsrs"]
 
+[lib]
+crate-type = ["cdylib"]
+
 [features]
 default = []
 qrcode = ["matrix-qrcode"]
diff --git a/crates/matrix-sdk-crypto/src/lib.rs b/crates/matrix-sdk-crypto/src/lib.rs
index d98dfd56b..2f58f8418 100644
--- a/crates/matrix-sdk-crypto/src/lib.rs
+++ b/crates/matrix-sdk-crypto/src/lib.rs
@@ -15,8 +15,7 @@
 #![doc = include_str!("../README.md")]
 #![cfg_attr(docsrs, feature(doc_auto_cfg))]
 #![warn(missing_docs, missing_debug_implementations)]
-
-#[cfg(all(feature = "js", not(target_arch = "wasm32")))]
+#![cfg(all(feature = "js", not(target_arch = "wasm32")))]
 compile_error!(
     "The `js` feature must be enabled only for the `wasm32` target (either `wasm32-unknown-unknown` or `wasm32-wasi`)."
 );