diff --git a/jedi/inference/compiled/mixed.py b/jedi/inference/compiled/mixed.py
index e96957ed..86675794 100644
--- a/jedi/inference/compiled/mixed.py
+++ b/jedi/inference/compiled/mixed.py
@@ -4,6 +4,7 @@ Used only for REPL Completion.
 
 import inspect
 import os
+from pathlib import Path
 
 from jedi.parser_utils import get_cached_code_lines
 
@@ -190,7 +191,8 @@ def _find_syntax_node_name(inference_state, python_object):
     except TypeError:
         # The type might not be known (e.g. class_with_dict.__weakref__)
         return None
-    if path is None or not os.path.exists(path):
+    path = None if path is None else Path(path)
+    if path is None or not path.exists():
         # The path might not exist or be e.g. <stdin>.
         return None
 
diff --git a/jedi/inference/compiled/subprocess/functions.py b/jedi/inference/compiled/subprocess/functions.py
index 9aa1cb2e..601fe6c2 100644
--- a/jedi/inference/compiled/subprocess/functions.py
+++ b/jedi/inference/compiled/subprocess/functions.py
@@ -3,6 +3,7 @@ import os
 import inspect
 import importlib
 import warnings
+from pathlib import Path
 from zipimport import zipimporter
 from importlib.machinery import all_suffixes
 
@@ -211,7 +212,7 @@ def _from_loader(loader, string):
     if code is None:
         return None, is_package
     if isinstance(loader, zipimporter):
-        return ZipFileIO(module_path, code, cast_path(loader.archive)), is_package
+        return ZipFileIO(module_path, code, Path(cast_path(loader.archive))), is_package
 
     return KnownContentFileIO(module_path, code), is_package
 
diff --git a/jedi/inference/references.py b/jedi/inference/references.py
index e1b97c41..07a840a1 100644
--- a/jedi/inference/references.py
+++ b/jedi/inference/references.py
@@ -203,11 +203,11 @@ def recurse_find_python_folders_and_files(folder_io, except_paths=()):
         # Delete folders that we don't want to iterate over.
         for file_io in file_ios:
             path = file_io.path
-            if path.endswith('.py') or path.endswith('.pyi'):
+            if path.suffix in ('.py', '.pyi'):
                 if path not in except_paths:
                     yield None, file_io
 
-            if path.endswith('.gitignore'):
+            if path.name == '.gitignore':
                 ignored_paths, ignored_names = \
                     gitignored_lines(root_folder_io, file_io)
                 except_paths |= ignored_paths
diff --git a/jedi/inference/sys_path.py b/jedi/inference/sys_path.py
index b7457e88..0f44be4a 100644
--- a/jedi/inference/sys_path.py
+++ b/jedi/inference/sys_path.py
@@ -164,7 +164,7 @@ def _get_paths_from_buildout_script(inference_state, buildout_script_path):
         inference_state, module_node,
         file_io=file_io,
         string_names=None,
-        code_lines=get_cached_code_lines(inference_state.grammar, str(buildout_script_path)),
+        code_lines=get_cached_code_lines(inference_state.grammar, buildout_script_path),
     ).as_context()
     yield from check_sys_path_modifications(module_context)
 
diff --git a/test/test_api/test_api.py b/test/test_api/test_api.py
index c86be78c..1829e30f 100644
--- a/test/test_api/test_api.py
+++ b/test/test_api/test_api.py
@@ -15,7 +15,7 @@ from test.helpers import test_dir, get_example_dir
 
 
 def test_preload_modules():
-    def check_loaded(*modules):
+    def check_loaded(*module_names):
         for grammar_cache in cache.parser_cache.values():
             if None in grammar_cache:
                 break
@@ -25,9 +25,9 @@ def test_preload_modules():
             if path is not None and str(path).startswith(str(typeshed.TYPESHED_PATH))
         )
         # +1 for None module (currently used)
-        assert len(grammar_cache) - typeshed_cache_count == len(modules) + 1
-        for i in modules:
-            assert [i in k for k in grammar_cache.keys() if k is not None]
+        assert len(grammar_cache) - typeshed_cache_count == len(module_names) + 1
+        for i in module_names:
+            assert [i in str(k) for k in grammar_cache.keys() if k is not None]
 
     old_cache = cache.parser_cache.copy()
     cache.parser_cache.clear()
diff --git a/test/test_inference/test_imports.py b/test/test_inference/test_imports.py
index 32acf093..f1eb3f57 100644
--- a/test/test_inference/test_imports.py
+++ b/test/test_inference/test_imports.py
@@ -29,13 +29,13 @@ def test_find_module_basic():
 
 def test_find_module_package():
     file_io, is_package = _find_module('json')
-    assert file_io.path.endswith(os.path.join('json', '__init__.py'))
+    assert file_io.path.parts[-2:] == ('json', '__init__.py')
     assert is_package is True
 
 
 def test_find_module_not_package():
     file_io, is_package = _find_module('io')
-    assert file_io.path.endswith('io.py')
+    assert file_io.path.name == 'io.py'
     assert is_package is False
 
 
@@ -55,8 +55,8 @@ def test_find_module_package_zipped(Script, inference_state, environment):
         full_name='pkg'
     )
     assert file_io is not None
-    assert file_io.path.endswith(os.path.join('pkg.zip', 'pkg', '__init__.py'))
-    assert file_io._zip_path.endswith('pkg.zip')
+    assert file_io.path.parts[-3:] == ('pkg.zip', 'pkg', '__init__.py')
+    assert file_io._zip_path.name == 'pkg.zip'
     assert is_package is True
 
 
@@ -108,7 +108,7 @@ def test_find_module_not_package_zipped(Script, inference_state, environment):
         string='not_pkg',
         full_name='not_pkg'
     )
-    assert file_io.path.endswith(os.path.join('not_pkg.zip', 'not_pkg.py'))
+    assert file_io.path.parts[-2:] == ('not_pkg.zip', 'not_pkg.py')
     assert is_package is False