diff --git a/appium/webdriver/webdriver.py b/appium/webdriver/webdriver.py
index 4584824b..6ca1867c 100644
--- a/appium/webdriver/webdriver.py
+++ b/appium/webdriver/webdriver.py
@@ -431,7 +431,7 @@ def orientation(self, value: str) -> None:
         """
         allowed_values = ['LANDSCAPE', 'PORTRAIT']
         if value.upper() in allowed_values:
-            self.execute(Command.SET_SCREEN_ORIENTATION, {'orientation': value})
+            self.execute(Command.SET_SCREEN_ORIENTATION, {'orientation': value.upper()})
         else:
             raise WebDriverException("You can only set the orientation to 'LANDSCAPE' and 'PORTRAIT'")
 
diff --git a/test/unit/webdriver/webdriver_test.py b/test/unit/webdriver/webdriver_test.py
index 36102735..1ccaedd9 100644
--- a/test/unit/webdriver/webdriver_test.py
+++ b/test/unit/webdriver/webdriver_test.py
@@ -404,6 +404,21 @@ class CustomAppiumConnection(AppiumConnection):
 
         assert isinstance(driver.command_executor, CustomAppiumConnection)
 
+    @httpretty.activate
+    def test_orientation_setter_normalizes_case(self):
+        driver = android_w3c_driver()
+        httpretty.register_uri(httpretty.POST, appium_command('/session/1234567890/orientation'), body='{"value": ""}')
+
+        driver.orientation = 'landscape'
+        assert get_httpretty_request_body(httpretty.last_request()) == {
+            'orientation': 'LANDSCAPE',
+        }
+
+        driver.orientation = 'portrait'
+        assert get_httpretty_request_body(httpretty.last_request()) == {
+            'orientation': 'PORTRAIT',
+        }
+
     @httpretty.activate
     def test_extention_command_check(self):
         driver = android_w3c_driver()