diff --git a/scripts/tests/test_validate_docstrings.py b/scripts/tests/test_validate_docstrings.py
index 120f8d79819ff..9f304a3f194ba 100644
--- a/scripts/tests/test_validate_docstrings.py
+++ b/scripts/tests/test_validate_docstrings.py
@@ -6,7 +6,7 @@
 import numpy as np
 import pandas as pd
 
-import validate_docstrings
+from scripts import validate_docstrings
 validate_one = validate_docstrings.validate_one
 
 
@@ -1052,6 +1052,11 @@ def test_raises_for_invalid_attribute_name(self, invalid_name):
         with pytest.raises(AttributeError, match=msg):
             validate_docstrings.Docstring(invalid_name)
 
+    @pytest.mark.parametrize('name', ['pandas.Series.str.isdecimal'])
+    def test_encode_content_write_to_file(self, name):
+        docstr = validate_docstrings.Docstring(name).validate_pep8()
+        assert len(list(docstr)) == 0
+
 
 class TestMainFunction(object):
     def test_exit_status_for_validate_one(self, monkeypatch):
@@ -1149,4 +1154,4 @@ def test_errors_param_filters_errors(self, monkeypatch):
                                                errors=['ER03'],
                                                output_format='default',
                                                ignore_deprecated=False)
-        assert exit_status == 1
+        assert exit_status == 1
\ No newline at end of file
diff --git a/scripts/validate_docstrings.py b/scripts/validate_docstrings.py
index 1173b34b2e430..035d3dd527b45 100755
--- a/scripts/validate_docstrings.py
+++ b/scripts/validate_docstrings.py
@@ -580,8 +580,8 @@ def validate_pep8(self):
         application = flake8.main.application.Application()
         application.initialize(["--quiet"])
 
-        with tempfile.NamedTemporaryFile(mode='w') as file:
-            file.write(content)
+        with tempfile.NamedTemporaryFile(mode='wb') as file:
+            file.write(content.encode("utf-8"))
             file.flush()
             application.run_checks([file.name])