diff --git a/core/src/lib.rs b/core/src/lib.rs
index 54f9157..e6d3594 100644
--- a/core/src/lib.rs
+++ b/core/src/lib.rs
@@ -1,4 +1,4 @@
-//#![cfg_attr(not(any(test, feature = "std")), no_std)]
+#![cfg_attr(not(any(test, feature = "std")), no_std)]
 
 #[cfg(feature = "alloc")]
 extern crate alloc;