diff --git a/starky/src/fibonacci_stark.rs b/starky/src/fibonacci_stark.rs
index 156b14f8..69ff2450 100644
--- a/starky/src/fibonacci_stark.rs
+++ b/starky/src/fibonacci_stark.rs
@@ -191,13 +191,13 @@ mod tests {
         )?;
         verify(stark, proof.clone(), &config)?;
 
-        recursive_proof::<F, C, S, C, D>(stark, proof, &config, true, true)
+        recursive_proof::<F, C, S, C, D>(stark, proof, &config, true)
     }
 
     fn recursive_proof<
         F: RichField + Extendable<D>,
         C: GenericConfig<D, F = F>,
-        S: Stark<F, D>,
+        S: Stark<F, D> + Copy,
         InnerC: GenericConfig<D, F = F>,
         const D: usize,
     >(
diff --git a/starky/src/stark.rs b/starky/src/stark.rs
index 888dc004..3ef976e0 100644
--- a/starky/src/stark.rs
+++ b/starky/src/stark.rs
@@ -14,7 +14,7 @@ use crate::vars::StarkEvaluationVars;
 
 /// Represents a STARK system.
 // TODO: Add a `constraint_degree` fn that returns the maximum constraint degree.
-pub trait Stark<F: RichField + Extendable<D>, const D: usize>: Sync + Copy {
+pub trait Stark<F: RichField + Extendable<D>, const D: usize>: Sync {
     /// The total number of columns in the trace.
     const COLUMNS: usize;
     /// The number of public inputs.