diff --git a/refinery/units/formats/pym.py b/refinery/units/formats/pym.py
index 5c228623e1..b5dec0694a 100644
--- a/refinery/units/formats/pym.py
+++ b/refinery/units/formats/pym.py
@@ -2,7 +2,6 @@
 # -*- coding: utf-8 -*-
 from refinery.units import Unit
 
-import importlib
 import marshal
 
 
@@ -16,6 +15,44 @@ class pym(Unit):
     refer to the official Python documentation for more details.
     """
 
+    def reverse(self, data):
+        return marshal.dumps(data)
+
     def process(self, data):
-        # https://stackoverflow.com/a/73454818
-        return importlib._bootstrap_external._code_to_timestamp_pyc(marshal.loads(data))
+        data = marshal.loads(data)
+        code = (lambda: 0).__code__.__class__
+
+        def toblob(data):
+            if isinstance(data, (bytes, bytearray)):
+                self.log_info(U'unmarshalled a byte string, returning as is')
+                return data
+            if isinstance(data, str):
+                self.log_info(F'unmarshalled a string object, encoding as {self.codec}')
+                return data.encode(self.codec)
+            if isinstance(data, code):
+                self.log_info(U'unmarshalled a code object, converting to pyc')
+                import importlib
+                return importlib._bootstrap_external._code_to_timestamp_pyc(data)
+            if isinstance(data, int):
+                self.log_info(U'unmarshalled an integer, returning big endian encoding')
+                q, r = divmod(data.bit_length(), 8)
+                q += int(bool(r))
+                return data.to_bytes(q, 'big')
+            if isinstance(data, dict):
+                try:
+                    import json
+                    serialized = json.dumps(data, indent=4)
+                except Exception:
+                    pass
+                else:
+                    self.log_info(U'unmarshalled a serializable dictionary, returning JSON')
+                    return serialized.encode(self.codec)
+            raise NotImplementedError(
+                F'No serialization implemented for object of type {data.__class__.__name__}')
+
+        if isinstance(data, list):
+            self.log_info('object is a list, converting each item individually')
+            for item in data:
+                yield toblob(item)
+        else:
+            yield toblob(data)
diff --git a/test/units/formats/test_pym.py b/test/units/formats/test_pym.py
new file mode 100644
index 0000000000..9cfe4d022f
--- /dev/null
+++ b/test/units/formats/test_pym.py
@@ -0,0 +1,57 @@
+#!/usr/bin/env python3
+# -*- coding: utf-8 -*-
+import marshal
+import json
+
+from .. import TestUnitBase
+
+
+class TestPyMarshal(TestUnitBase):
+
+    def test_integer(self):
+        unit = self.load()
+        data = 935532112
+        test = marshal.dumps(data) | unit | bytes
+        self.assertEqual(int.from_bytes(test, 'big'), data)
+
+    def test_string(self):
+        unit = self.load()
+        data = 'The binary refinery refines the finest binaries.'
+        test = marshal.dumps(data) | unit | str
+        self.assertEqual(test, data)
+
+    def test_strings(self):
+        unit = self.load()
+        data = 'The binary refinery refines the finest binaries.'.split()
+        test = marshal.dumps(data) | unit | [str]
+        self.assertEqual(test, data)
+
+    def test_json(self):
+        unit = self.load()
+        data = {
+            'foo': None,
+            'bar': [1, 12, 7],
+            'baz': {
+                'x': 'refined',
+                'y': 'binaries',
+            }
+        }
+        test = marshal.dumps(data) | unit | json.loads
+        self.assertEqual(test, data)
+
+    def test_bytes(self):
+        unit = self.load()
+        for k in (1, 2, 12, 200, 353444):
+            t = self.generate_random_buffer(k)
+            self.assertEqual(marshal.dumps(t) | unit | bytes, t)
+
+    def test_code(self):
+        def test_function():
+            print('refine your binaries!')
+
+        from refinery.units.formats.pyc import pyc
+        from refinery.units.formats.pym import pym
+
+        data = marshal.dumps(test_function.__code__)
+        test = data | pym | pyc | str
+        self.assertIn('refine your binaries!', test)