diff --git a/src/util/psbt/error.rs b/src/util/psbt/error.rs
index b1fd7337..b5dd63f9 100644
--- a/src/util/psbt/error.rs
+++ b/src/util/psbt/error.rs
@@ -68,9 +68,9 @@ pub enum Error {
         /// Hash-type
         hash_type: PsbtHash,
         /// Pre-image
-        preimage: Vec<u8>,
+        preimage: Box<[u8]>,
         /// Hash value
-        hash: Vec<u8>,
+        hash: Box<[u8]>,
     },
     /// Data inconsistency/conflicting data during merge procedure
     MergeConflict(String),
diff --git a/src/util/psbt/map/input.rs b/src/util/psbt/map/input.rs
index ddcc1f8a..ea6274f5 100644
--- a/src/util/psbt/map/input.rs
+++ b/src/util/psbt/map/input.rs
@@ -311,8 +311,8 @@ where
             let val: Vec<u8> = Deserialize::deserialize(&raw_value)?;
             if <H as hashes::Hash>::hash(&val) != key_val {
                 return Err(psbt::Error::InvalidPreimageHashPair {
-                    preimage: val,
-                    hash: Vec::from(key_val.borrow()),
+                    preimage: val.into_boxed_slice(),
+                    hash: Box::from(key_val.borrow()),
                     hash_type: hash_type,
                 }
                 .into());