diff --git a/bitcoin/src/psbt/mod.rs b/bitcoin/src/psbt/mod.rs
index 0dcd4b51..1b43d5e1 100644
--- a/bitcoin/src/psbt/mod.rs
+++ b/bitcoin/src/psbt/mod.rs
@@ -798,12 +798,12 @@ impl fmt::Display for IndexOutOfBoundsError {
             Inputs { ref index, ref length } => write!(
                 f,
                 "index {} is out-of-bounds for PSBT inputs vector length {}",
-                length, index
+                index, length
             ),
             TxInput { ref index, ref length } => write!(
                 f,
                 "index {} is out-of-bounds for PSBT unsigned tx input vector length {}",
-                length, index
+                index, length
             ),
         }
     }