diff --git a/pyproject.toml b/pyproject.toml
index bb9d64e..1795671 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -1,7 +1,7 @@
 
 [project]
 name = "jo3util"
-version = "0.0.6"
+version = "0.0.7"
 description = ""
 dependencies = []
 dynamic = ["readme"]
diff --git a/src/eqx.py b/src/eqx.py
index 11b4f09..d13e74c 100644
--- a/src/eqx.py
+++ b/src/eqx.py
@@ -1,7 +1,8 @@
 #! /usr/bin/env python3
 
 import json
-from typing import Callable, Optional, Tuple
+from typing import Callable, Optional, Tuple, Union
+from pathlib import Path
 
 import equinox as eqx
 import jax
@@ -95,7 +96,11 @@ def sow(where: Callable, model: eqx.Module) -> eqx.Module:
     return Sow(model)
 
 
-def insert_after(where: Callable, model: eqx.Module, func: Callable) -> eqx.Module:
+def insert_after(
+    where: Callable,
+    model: eqx.Module,
+    func: Callable
+) -> eqx.Module:
     """Place a callable immediately after the argument modules"""
 
     class Ensemble(eqx.Module):
@@ -116,9 +121,12 @@ def insert_after(where: Callable, model: eqx.Module, func: Callable) -> eqx.Modu
     return model
 
 
-def save(path, pytree, hyperparameters={}):
+def save(path: Union[Path, str], pytree, hyperparameters={}):
     with open(path, "wb") as f:
-        hyperparameters = json.dumps(hyperparameters)
+        hyperparameters = json.dumps(
+            hyperparameters,
+            default=lambda h: vars(h)
+        )
         f.write((hyperparameters + "\n").encode())
         eqx.tree_serialise_leaves(f, pytree)
 
diff --git a/src/main.py b/src/main.py
deleted file mode 100644
index 9789cc1..0000000
--- a/src/main.py
+++ /dev/null
@@ -1,7 +0,0 @@
-#! /usr/bin/env python3
-# vim:fenc=utf-8
-
-"""
-
-"""
-