diff --git a/appium/webdriver/webdriver.py b/appium/webdriver/webdriver.py
index 5410409e..add39593 100644
--- a/appium/webdriver/webdriver.py
+++ b/appium/webdriver/webdriver.py
@@ -458,7 +458,7 @@ 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 33123043..925b013d 100644
--- a/test/unit/webdriver/webdriver_test.py
+++ b/test/unit/webdriver/webdriver_test.py
@@ -486,6 +486,21 @@ def test_orientation_setter(self):
             'orientation': 'PORTRAIT',
         }
 
+    @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_orientation_setter_invalid(self):
         driver = android_w3c_driver()