diff --git a/swiftsimio/_array_functions.py b/swiftsimio/_array_functions.py
index dac6a642..1a5219b3 100644
--- a/swiftsimio/_array_functions.py
+++ b/swiftsimio/_array_functions.py
@@ -1188,24 +1188,26 @@ def linalg_det(a):
 #     return _return_helper(res, helper_result, ret_cf, out=out)
 
 
-# @implements(np.diff)
-# def diff(...):
-#     from unyt._array_functions import diff as unyt_diff
+@implements(np.diff)
+def diff(a, n=1, axis=-1, prepend=np._NoValue, append=np._NoValue):
+    from unyt._array_functions import diff as unyt_diff
 
-#     helper_result = _prepare_array_func_args(...)
-#     ret_cf = ...()
-#     res = unyt_diff(*helper_result["args"], **helper_result["kwargs"])
-#     return _return_helper(res, helper_result, ret_cf, out=out)
+    helper_result = _prepare_array_func_args(
+        a, n=n, axis=axis, prepend=prepend, append=append
+    )
+    ret_cf = _preserve_cosmo_factor(helper_result["ca_cfs"][0])
+    res = unyt_diff(*helper_result["args"], **helper_result["kwargs"])
+    return _return_helper(res, helper_result, ret_cf)
 
 
-# @implements(np.ediff1d)
-# def ediff1d(...):
-#     from unyt._array_functions import ediff1d as unyt_ediff1d
+@implements(np.ediff1d)
+def ediff1d(ary, to_end=None, to_begin=None):
+    from unyt._array_functions import ediff1d as unyt_ediff1d
 
-#     helper_result = _prepare_array_func_args(...)
-#     ret_cf = ...()
-#     res = unyt_ediff1d(*helper_result["args"], **helper_result["kwargs"])
-#     return _return_helper(res, helper_result, ret_cf, out=out)
+    helper_result = _prepare_array_func_args(ary, to_end=to_end, to_begin=to_begin)
+    ret_cf = _preserve_cosmo_factor(helper_result["ca_cfs"][0])
+    res = unyt_ediff1d(*helper_result["args"], **helper_result["kwargs"])
+    return _return_helper(res, helper_result, ret_cf)
 
 
 # @implements(np.ptp)
diff --git a/swiftsimio/objects.py b/swiftsimio/objects.py
index f4ce1861..d6c60d29 100644
--- a/swiftsimio/objects.py
+++ b/swiftsimio/objects.py
@@ -443,10 +443,7 @@ def _prepare_array_func_args(*args, **kwargs):
     else:
         # mixed compressions, strip it off
         ret_comp = None
-    args = [unyt_array(arg) if isinstance(arg, cosmo_array) else arg for arg in args]
-    kwargs = {
-        k: unyt_array(v) if isinstance(v, cosmo_array) else v for k, v in kwargs.items()
-    }
+    # WE SHOULD COMPLAIN HERE IF WE HAVE DIFFERENT SCALE FACTORS IN COSMO_FACTOR'S??
     return dict(
         args=args,
         kwargs=kwargs,
diff --git a/tests/test_cosmo_array.py b/tests/test_cosmo_array.py
index a16a3dbc..112876be 100644
--- a/tests/test_cosmo_array.py
+++ b/tests/test_cosmo_array.py
@@ -155,8 +155,8 @@ def test_handled_funcs(self):
             # "nanpercentile": (ca(np.arange(3)), 30),
             # "nanquantile": (ca(np.arange(3)), 0.3),
             "linalg.det": (ca(np.eye(3)),),
-            # "diff": (ca(np.arange(3)),),
-            # "ediff1d": (ca(np.arange(3)),),
+            "diff": (ca(np.arange(3)),),
+            "ediff1d": (ca(np.arange(3)),),
             # "ptp": (ca(np.arange(3)),),
             "cumprod": (ca(np.arange(3)),),
             # "pad": (ca(np.arange(3)), 3),