diff --git a/scrapy/exporters.py b/scrapy/exporters.py
index 145468dbe..c7c78d054 100644
--- a/scrapy/exporters.py
+++ b/scrapy/exporters.py
@@ -273,10 +273,10 @@ class PythonItemExporter(BaseItemExporter):
             return dict(self._serialize_dict(value))
         if is_listlike(value):
             return [self._serialize_value(v) for v in value]
-        if self.binary:
-            return to_bytes(value, encoding=self.encoding)
-        else:
-            return to_unicode(value, encoding=self.encoding)
+        encode_func = to_bytes if self.binary else to_unicode
+        if isinstance(value, (six.text_type, bytes)):
+            return encode_func(value, encoding=self.encoding)
+        return value
 
     def _serialize_dict(self, value):
         for key, val in six.iteritems(value):
diff --git a/tests/test_exporters.py b/tests/test_exporters.py
index 1633e1039..662f8ec5c 100644
--- a/tests/test_exporters.py
+++ b/tests/test_exporters.py
@@ -134,6 +134,19 @@ class PythonItemExporterTest(BaseItemExporterTest):
         expected = {b'name': b'John\xc2\xa3', b'age': b'22'}
         self.assertEqual(expected, exporter.export_item(value))
 
+    def test_other_python_types_item(self):
+        from datetime import datetime
+        now = datetime.now()
+        item = {
+            'boolean': False,
+            'number': 22,
+            'time': now,
+            'float': 3.14,
+        }
+        ie = self._get_exporter()
+        exported = ie.export_item(item)
+        self.assertEqual(exported, item)
+
 
 class PprintItemExporterTest(BaseItemExporterTest):