diff --git a/CHANGES.rst b/CHANGES.rst
index 354300967..0af01f647 100644
--- a/CHANGES.rst
+++ b/CHANGES.rst
@@ -6,6 +6,8 @@ Version 8.4.1
 Unreleased
 
 -   Zsh completion scripts parse correctly on Windows. :issue:`3277`
+-   Shell completion of `Choice` `Enum` values produces a valid completion
+    result. :issue:`3015`
 
 
 Version 8.4.0
diff --git a/src/click/types.py b/src/click/types.py
index 556f20f2b..1ca3e9b5d 100644
--- a/src/click/types.py
+++ b/src/click/types.py
@@ -408,8 +408,7 @@ def shell_complete(
         """
         from click.shell_completion import CompletionItem
 
-        str_choices = map(str, self.choices)
-
+        str_choices = [self.normalize_choice(choice, ctx) for choice in self.choices]
         if self.case_sensitive:
             matched = (c for c in str_choices if c.startswith(incomplete))
         else:
diff --git a/tests/test_shell_completion.py b/tests/test_shell_completion.py
index 23c5ff05c..6d9a58305 100644
--- a/tests/test_shell_completion.py
+++ b/tests/test_shell_completion.py
@@ -473,7 +473,8 @@ def complete(ctx, param, incomplete):
     assert result.output == "plain,a\nplain,b\n"
 
 
-@pytest.mark.parametrize(("value", "expect"), [(False, ["Au", "al"]), (True, ["al"])])
+# case_sensitive=False normalizes values to lowercase, matching remains case insensitive
+@pytest.mark.parametrize(("value", "expect"), [(False, ["au", "al"]), (True, ["al"])])
 def test_choice_case_sensitive(value, expect):
     cli = Command(
         "cli",