diff --git a/README.md b/README.md
index 1f4cdf4..29c81ff 100644
--- a/README.md
+++ b/README.md
@@ -49,7 +49,7 @@ class Model(eqx.Module):
 
     def __call__(self, hists: dict[str, Array]) -> Array:
         mu_modifier = self.mu.unconstrained()
-        syst_modifier = self.syst.lnN(width=jnp.array([0.9, 1.1]))
+        syst_modifier = self.syst.lnN(up=jnp.array([1.1]), down=jnp.array([0.9]))
         return mu_modifier(hists["signal"]) + syst_modifier(hists["bkg"])
 
 
diff --git a/src/evermore/modifier.py b/src/evermore/modifier.py
index 87c9b75..1d652e9 100644
--- a/src/evermore/modifier.py
+++ b/src/evermore/modifier.py
@@ -361,8 +361,9 @@ def scale_factor(self, hist: Array) -> SF:
             groups[jtu.tree_structure(mod)].append(mod)
         # then do the `jax.lax.scan` loops
         for _, group_mods in groups.items():
-            # Essentially we are turning an array of modifiers into a single modifier with a stack of scale factors and effect leaves (e.g. `width`).
-            # Then we can use XLA's loop constructs (e.g.: `jax.lax.scan`) to calculate the scale factors without having to compile the fully unrolled loop.
+            # Essentially we are turning an array of modifiers into a single modifier of stacked leaves.
+            # Then we can use XLA's loop constructs (e.g.: `jax.lax.scan`) to calculate the scale factors
+            # without having to compile the fully unrolled loop.
             stack = tree_stack(group_mods, broadcast_leaves=True)  # type: ignore[arg-type]
             # scan over first axis of stack
             dynamic_stack, static_stack = eqx.partition(stack, eqx.is_array)