diff --git a/linkcheck/htmlutil/loginformsearch.py b/linkcheck/htmlutil/loginformsearch.py
index d10b5089..e8a4cd53 100644
--- a/linkcheck/htmlutil/loginformsearch.py
+++ b/linkcheck/htmlutil/loginformsearch.py
@@ -42,16 +42,14 @@ def search_form(content, cgiuser, cgipassword):
     CGI fields. If no form is found return None.
     """
     soup = htmlsoup.make_soup(content)
-    # The value of the name attribute is case-insensitive
-    # https://www.w3.org/TR/html401/interact/forms.html#adef-name-INPUT
-    cginames = {cgiuser.lower(), cgipassword.lower()}
+    cginames = {cgiuser, cgipassword}
     for form_element in soup.find_all("form", action=True):
         form = Form(form_element["action"])
         for input_element in form_element.find_all("input",
                                                    attrs={"name": True}):
             form.add_value(
                 input_element["name"], input_element.attrs.get("value"))
-        if cginames <= {x.lower() for x in form.data}:
+        if cginames <= set(form.data):
             log.debug(LOG_CHECK, "Found form %s", form)
             return form
 
diff --git a/tests/test_loginformsearch.py b/tests/test_loginformsearch.py
index 866e498f..6c2dab16 100644
--- a/tests/test_loginformsearch.py
+++ b/tests/test_loginformsearch.py
@@ -43,7 +43,7 @@ class TestFormSearch(unittest.TestCase):
 
     def test_search_form(self):
         form = loginformsearch.search_form(login_form,
-                                           "USER_FIELD", "password_field")
+                                           "User_Field", "Password_Field")
         self.assertIsNotNone(form)
         self.assertEqual(form.url, "/log_me_in")
         self.assertIn("User_Field", form.data)
@@ -51,5 +51,5 @@ class TestFormSearch(unittest.TestCase):
 
     def test_search_form_none(self):
         form = loginformsearch.search_form(login_form,
-                                           "nouser", "nopassword")
+                                           "user_field", "password_field")
         self.assertIsNone(form)