diff --git a/substrate/state-machine/src/lib.rs b/substrate/state-machine/src/lib.rs
index e497a20474..f0c1d17b8b 100644
--- a/substrate/state-machine/src/lib.rs
+++ b/substrate/state-machine/src/lib.rs
@@ -19,7 +19,8 @@
 #![warn(missing_docs)]
 
 extern crate polkadot_primitives as primitives;
-#[macro_use]
+
+#[cfg_attr(test, macro_use)]
 extern crate hex_literal;
 
 extern crate hashdb;