diff --git a/bsplines2d/_class02_BSplines2D.py b/bsplines2d/_class02_BSplines2D.py
index 6f81c83..bcd9aa3 100644
--- a/bsplines2d/_class02_BSplines2D.py
+++ b/bsplines2d/_class02_BSplines2D.py
@@ -1204,9 +1204,11 @@ def plot_as_profile2d_compare(
 
     def save(
         self,
+        pfe=None,
         path=None,
         name=None,
         sep=None,
+        overwrite=None,
         verb=True,
         return_pfe=False,
     ):
@@ -1220,9 +1222,11 @@ def save(
         # call inherited method
 
         out = super().save(
+            pfe=pfe,
             path=path,
             name=name,
             sep=sep,
+            overwrite=overwrite,
             verb=verb,
             return_pfe=return_pfe,
         )
diff --git a/bsplines2d/_saveload.py b/bsplines2d/_saveload.py
index fccea30..8b6ea6e 100644
--- a/bsplines2d/_saveload.py
+++ b/bsplines2d/_saveload.py
@@ -54,6 +54,7 @@ def restore_bsplines(coll=None, dclas=None):
 def load(
     pfe=None,
     cls=None,
+    coll=None,
     allow_pickle=None,
     sep=None,
     verb=None,
@@ -71,6 +72,7 @@ def load(
     coll = ds.load(
         pfe=pfe,
         cls=cls,
+        coll=coll,
         allow_pickle=allow_pickle,
         sep=sep,
         verb=verb,
diff --git a/bsplines2d/tests/test_01_Mesh2D.py b/bsplines2d/tests/test_01_Mesh2D.py
index 4f32697..c34902b 100644
--- a/bsplines2d/tests/test_01_Mesh2D.py
+++ b/bsplines2d/tests/test_01_Mesh2D.py
@@ -374,4 +374,19 @@ def test59_saveload_equal(self):
         os.remove(pfe)
 
         # equal
-        assert self.bs == out
\ No newline at end of file
+        assert self.bs == out
+
+    def test60_saveload_coll(self):
+
+        # save
+        pfe = self.bs.save(return_pfe=True)
+
+        # load
+        coll = BSplines2D()
+        coll = _saveload.load(pfe, coll=coll)
+
+        # remove file
+        os.remove(pfe)
+
+        # equal
+        assert self.bs == coll
\ No newline at end of file
diff --git a/bsplines2d/version.py b/bsplines2d/version.py
index dfc5440..0a9a364 100644
--- a/bsplines2d/version.py
+++ b/bsplines2d/version.py
@@ -1,2 +1,2 @@
 # Do not edit, pipeline versioning governed by git tags!
-__version__ = '0.0.18'
+__version__ = '0.0.19'
diff --git a/requirements.txt b/requirements.txt
index 54dd717..56486ad 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -4,4 +4,4 @@ scipy
 matplotlib
 astropy
 contourpy
-datastock>=0.0.42
+datastock>=0.0.44
diff --git a/setup.py b/setup.py
index bb696bd..ab829f4 100644
--- a/setup.py
+++ b/setup.py
@@ -123,7 +123,7 @@
         "matplotlib",
         "astropy",
         "contourpy",
-        "datastock>=0.0.42",
+        "datastock>=0.0.44",
     ],
     python_requires=">=3.6",