diff --git a/tests/test_locations.py b/tests/test_locations.py
index aa1edcdc..80b1cbde 100644
--- a/tests/test_locations.py
+++ b/tests/test_locations.py
@@ -154,6 +154,11 @@ def test_urlsplit(self):
         )
 
     def test_path_from_uri(self):
+        if platform.system() == 'Windows':
+            default_class = LocationWindowsPath
+        else:
+            default_class = LocationPosixPath
+
         with self.assertRaises(ValueError) as ec:
             LocationPath.from_uri('')
         self.assertEqual(str(ec.exception), 'Empty URI provided!')
@@ -163,11 +168,11 @@ def test_path_from_uri(self):
         self.assertEqual(str(path), '/names')
 
         path = LocationPosixPath.from_uri('file:///home/foo/names/?name=foo')
-        self.assertIsInstance(path, LocationPosixPath)
+        self.assertIsInstance(path, default_class)
         self.assertEqual(str(path), '/home/foo/names')
 
         path = LocationPosixPath.from_uri('file:///home/foo/names#foo')
-        self.assertIsInstance(path, LocationPosixPath)
+        self.assertIsInstance(path, default_class)
         self.assertEqual(str(path), '/home/foo/names')
 
         path = LocationPath.from_uri('file:///home\\foo\\names#foo')
@@ -197,7 +202,6 @@ def test_path_from_uri(self):
     def test_get_uri(self):
         for url in URL_CASES:
             self.assertEqual(get_uri(*urlsplit(url)), url)
-            self.assertEqual(get_uri(*urlsplit(f' {url}')), url)
 
         url = 'D:/a/xmlschema/xmlschema/tests/test_cases/examples/'
         self.assertNotEqual(get_uri(*urlsplit(url)), url)
@@ -205,13 +209,13 @@ def test_get_uri(self):
         # Test urlsplit() roundtrip with urlunsplit()
         for url in URL_CASES:
             if url == 'file:other.xsd':
+                # https://datatracker.ietf.org/doc/html/rfc8089#appendix-E.2.1
                 if sys.version_info < (3, 13):
                     self.assertNotEqual(urlsplit(url).geturl(), url)
             elif url.startswith(('////', 'file:////')) and not is_unc_path('////'):
                 self.assertNotEqual(urlsplit(url).geturl(), url)
             else:
                 self.assertEqual(urlsplit(url).geturl(), url)
-                self.assertEqual(urlsplit(f' {url}').geturl(), url)
 
     def test_get_uri_path(self):
         self.assertEqual(get_uri_path('https', 'host', 'path', 'id=7', 'types'),
@@ -370,7 +374,9 @@ def test_normalize_url_with_base_unc_path(self,):
             if is_unc_path('////filer01/MY_HOME/'):
                 self.assertEqual(url, 'file://////filer01/MY_HOME/dev/XMLSCHEMA/test.xsd')
             else:
-                self.assertEqual(url, 'file:///filer01/MY_HOME/dev/XMLSCHEMA/test.xsd')
+                self.assertEqual(
+                    url, f'file://{DRIVE_REGEX}/filer01/MY_HOME/dev/XMLSCHEMA/test.xsd'
+                )
 
         with patch.object(os, 'name', 'posix'):
             self.assertEqual(os.name, 'posix')
@@ -387,7 +393,9 @@ def test_normalize_url_with_base_unc_path(self,):
             if is_unc_path('////'):
                 self.assertEqual(url, 'file://////filer01/MY_HOME/dev/XMLSCHEMA/test.xsd')
             else:
-                self.assertEqual(url, 'file:///filer01/MY_HOME/dev/XMLSCHEMA/test.xsd')
+                self.assertEqual(
+                    url, f'file://{DRIVE_REGEX}/filer01/MY_HOME/dev/XMLSCHEMA/test.xsd'
+                )
 
     def test_normalize_url_slashes(self):
         # Issue #116
diff --git a/xmlschema/locations.py b/xmlschema/locations.py
index 002012f6..17551bcc 100644
--- a/xmlschema/locations.py
+++ b/xmlschema/locations.py
@@ -198,7 +198,7 @@ def normalize_url(url: str, base_url: Optional[str] = None,
     the whitespaces are replaced with `+` characters.
     :return: a normalized URL string.
     """
-    url_parts = urlsplit(url)
+    url_parts = urlsplit(url.lstrip())
     if not is_local_scheme(url_parts.scheme):
         return encode_url(url_parts.geturl(), method)
 
@@ -207,7 +207,7 @@ def normalize_url(url: str, base_url: Optional[str] = None,
         return path.normalize().as_uri()
 
     if base_url is not None:
-        base_url_parts = urlsplit(base_url)
+        base_url_parts = urlsplit(base_url.lstrip())
         base_path = LocationPath.from_uri(base_url)
 
         if is_local_scheme(base_url_parts.scheme):
@@ -328,7 +328,7 @@ def is_safe_url(url: str, method: str = 'xml') -> bool:
     query_quote = quote_plus if method == 'html' else quote
     query_unquote = unquote_plus if method == 'html' else unquote
 
-    parts = urlsplit(url)
+    parts = urlsplit(url.lstrip())
     path_safe = ':/\\' if is_local_scheme(parts.scheme) else '/'
 
     return parts.netloc == quote(unquote(parts.netloc), safe='@:') and \
@@ -345,7 +345,7 @@ def encode_url(url: str, method: str = 'xml') -> str:
         url = decode_url(url, method)
 
     query_quote = quote_plus if method == 'html' else quote
-    parts = urlsplit(url)
+    parts = urlsplit(url.lstrip())
     path_safe = ':/\\' if is_local_scheme(parts.scheme) else '/'
 
     return get_uri(