diff --git a/lib/src/hex_util.rs b/lib/src/hex_util.rs
index 5a1611e4a2..41999d3f83 100644
--- a/lib/src/hex_util.rs
+++ b/lib/src/hex_util.rs
@@ -71,7 +71,6 @@ fn iter_half_bytes(bytes: &[u8]) -> impl ExactSizeIterator<Item = u8> + '_ {
     })
 }
 
-#[cfg(test)]
 #[cfg(test)]
 mod tests {
     use super::*;