diff --git a/pyrs/src/lib.rs b/pyrs/src/lib.rs
index 9526f4bf..146c36f7 100644
--- a/pyrs/src/lib.rs
+++ b/pyrs/src/lib.rs
@@ -71,6 +71,10 @@ fn add_pass_module(py: Python, parent: &PyModule) -> PyResult<()> {
     let m = PyModule::new(py, "passes")?;
     m.add_function(wrap_pyfunction!(greedy_depth_reduce, m)?)?;
     m.add_class::<tket2::T2Op>()?;
+    m.add(
+        "PullForwardError",
+        py.get_type::<tket2::passes::PyPullForwardError>(),
+    )?;
     parent.add_submodule(m)?;
     Ok(())
 }
diff --git a/src/passes.rs b/src/passes.rs
index 7ca2cc90..b2339f09 100644
--- a/src/passes.rs
+++ b/src/passes.rs
@@ -6,6 +6,8 @@
 // pub mod squash;
 mod commutation;
 pub use commutation::apply_greedy_commutation;
+#[cfg(feature = "pyo3")]
+pub use commutation::PyPullForwardError;
 
 // use rayon::prelude::*;