diff --git a/flatten/src/lib.rs b/flatten/src/lib.rs
index dca6e389..6d273302 100644
--- a/flatten/src/lib.rs
+++ b/flatten/src/lib.rs
@@ -49,9 +49,10 @@ value is stringified and concatenated together.
 - **tuples**: tuple values are passed through directly.
 */
 
-#![cfg_attr(not(feature = "std"), no_std)]
+#![no_std]
 #![deny(missing_docs)]
 
+#[cfg(any(test, feature = "alloc"))]
 extern crate alloc;
 
 mod flattener;
diff --git a/flatten/src/map.rs b/flatten/src/map.rs
index 187ac0e9..a372b603 100644
--- a/flatten/src/map.rs
+++ b/flatten/src/map.rs
@@ -361,6 +361,8 @@ mod tests {
 
     use super::*;
 
+    use alloc::borrow::ToOwned;
+
     struct Outer<I> {
         a: i32,
         // #[sval(flatten)]