diff --git a/Cargo.toml b/Cargo.toml
index ecde4f4..5d17fcb 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -7,5 +7,5 @@ repository = "https://github.com/ewasm/ewasm-rust-api"
 description = "ewasm API for Rust"
 
 [features]
-default = [ "std" ]
+default = []
 std = []
diff --git a/src/lib.rs b/src/lib.rs
index e2d1053..8f8ac70 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -1,3 +1,5 @@
+#![cfg_attr(not(feature = "std"), no_std)]
+
 /// ewasm_api is a library used to interface with Ethereum's EEI in Ewasm, a set of enhancements to
 /// the Ethereum smart contract platform.
 /// ewasm_api exposes both a set of unsafe "native" functions representing the actual EEI