diff --git a/cmd/soroban-cli/src/tx/builder.rs b/cmd/soroban-cli/src/tx/builder.rs
index 89b7f8a24..be0c49051 100644
--- a/cmd/soroban-cli/src/tx/builder.rs
+++ b/cmd/soroban-cli/src/tx/builder.rs
@@ -21,4 +21,6 @@ pub use transaction::Transaction;
 pub enum Error {
     #[error("Transaction contains too many operations")]
     TooManyOperations,
+    #[error(transparent)]
+    BytesM(#[from] bytesm::Error),
 }
diff --git a/cmd/soroban-cli/src/tx/builder/bytesm.rs b/cmd/soroban-cli/src/tx/builder/bytesm.rs
index f416384a4..c3a074cde 100644
--- a/cmd/soroban-cli/src/tx/builder/bytesm.rs
+++ b/cmd/soroban-cli/src/tx/builder/bytesm.rs
@@ -9,13 +9,15 @@ pub struct Bytes64(pub xdr::BytesM<64>);
 pub enum Error {
     #[error(transparent)]
     Xdr(#[from] xdr::Error),
+    #[error(transparent)]
+    Hex(#[from] hex::FromHexError),
 }
 
 impl FromStr for Bytes64 {
-    type Err = xdr::Error;
+    type Err = Error;
 
     fn from_str(value: &str) -> Result<Self, Self::Err> {
-        Ok(Self(xdr::BytesM::<64>::try_from(value)?))
+        Ok(Self(xdr::BytesM::<64>::try_from(&hex::decode(value)?)?))
     }
 }