diff --git a/src/lib.rs b/src/lib.rs
index 103cd7e..b9de71e 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -88,6 +88,8 @@ pub mod frame;
 
 #[allow(dead_code)]
 mod fastcpy;
+
+#[cfg(not(all(feature = "safe-encode", feature = "safe-decode")))]
 #[allow(dead_code)]
 mod fastcpy_unsafe;