diff --git a/coins/firo/src/spark/chaum/multisig.rs b/coins/firo/src/spark/chaum/multisig.rs
index a9ef2880..eba34dd0 100644
--- a/coins/firo/src/spark/chaum/multisig.rs
+++ b/coins/firo/src/spark/chaum/multisig.rs
@@ -1,3 +1,5 @@
+use std::io::Read;
+
 use rand_core::{RngCore, CryptoRng, SeedableRng};
 use rand_chacha::ChaCha12Rng;
 
@@ -61,11 +63,11 @@ impl Algorithm<Secp256k1> for ChaumMultisig {
     vec![]
   }
 
-  fn process_addendum(
+  fn process_addendum<Re: Read>(
     &mut self,
     _: &FrostView<Secp256k1>,
     _: u16,
-    _: &[u8]
+    _: &mut Re
   ) -> Result<(), FrostError> {
     Ok(())
   }
diff --git a/coins/firo/src/tests/mod.rs b/coins/firo/src/tests/mod.rs
index dd2d2495..acd57c51 100644
--- a/coins/firo/src/tests/mod.rs
+++ b/coins/firo/src/tests/mod.rs
@@ -43,7 +43,7 @@ fn chaum_multisig() {
   #[allow(non_snake_case)]
   let mut S_T = vec![];
   let mut xz = vec![];
-  for _ in 0 .. 2 {
+  for _ in 0 .. 5 {
     let x = Scalar::random(&mut OsRng);
     let z = Scalar::random(&mut OsRng);