diff --git a/tests/test_utils.py b/tests/test_utils.py
index 6fcd885a..0b9a2a27 100644
--- a/tests/test_utils.py
+++ b/tests/test_utils.py
@@ -52,7 +52,6 @@ def test_filter_prefixes_any(self):
             prefix_filter_list,
             self.features,
             require_all_prefixes=False,
-            converter=original_msdf.converter,
         )
         self.assertEqual(len(filtered_df), 136)
 
@@ -61,11 +60,10 @@ def test_filter_prefixes_all(self):
         prefix_filter_list = ["x", "y"]
         original_msdf = self.msdf
         filtered_df = filter_prefixes(
-            original_msdf,
+            original_msdf.df,
             prefix_filter_list,
             self.features,
             require_all_prefixes=True,
-            converter=original_msdf.converter,
         )
         self.assertEqual(len(filtered_df), 40)
 
@@ -78,7 +76,6 @@ def test_filter_out_prefixes_any(self):
             prefix_filter_list,
             self.features,
             require_all_prefixes=False,
-            converter=original_msdf.converter,
         )
         self.assertEqual(len(filtered_df), 5)
 
@@ -91,7 +88,6 @@ def test_filter_out_prefixes_all(self):
             prefix_filter_list,
             self.features,
             require_all_prefixes=True,
-            converter=original_msdf.converter,
         )
         self.assertEqual(len(filtered_df), 101)
 
@@ -99,9 +95,7 @@ def test_remove_mappings(self):
         """Test remove mappings."""
         prefix_filter_list = ["x", "y"]
         original_msdf = self.msdf
-        filtered_df = filter_out_prefixes(
-            original_msdf.df, prefix_filter_list, self.features, converter=original_msdf.converter
-        )
+        filtered_df = filter_out_prefixes(original_msdf.df, prefix_filter_list, self.features)
         new_msdf = MappingSetDataFrame.with_converter(
             df=filtered_df,
             converter=original_msdf.converter,
@@ -116,9 +110,7 @@ def test_clean_prefix_map(self):
         """Test clean prefix map."""
         prefix_filter_list = ["x", "y"]
         original_msdf = self.msdf
-        filtered_df = filter_out_prefixes(
-            original_msdf.df, prefix_filter_list, self.features, converter=original_msdf.converter
-        )
+        filtered_df = filter_out_prefixes(original_msdf.df, prefix_filter_list, self.features)
         new_msdf = MappingSetDataFrame.with_converter(
             df=filtered_df,
             converter=original_msdf.converter,