--- a/testing/web-platform/meta/MANIFEST.json
+++ b/testing/web-platform/meta/MANIFEST.json
@@ -593582,17 +593582,17 @@
    "cbebfbd2413ea0b10f547ab66fcc7159898e684a",
    "wdspec"
   ],
   "webdriver/tests/execute_script/user_prompts.py": [
    "901487f8270dcce693867ca090393e093d26f22b",
    "wdspec"
   ],
   "webdriver/tests/fullscreen_window.py": [
-   "817011a8cdff7cfd7e445fb8ecb84e5d91f03993",
+   "f16fb7a341a75e6a1a2c4bf9513df7b626cd07a3",
    "wdspec"
   ],
   "webdriver/tests/get_window_rect.py": [
    "c9139c16aa950c734c776887d6a762b867790812",
    "wdspec"
   ],
   "webdriver/tests/interaction/element_clear.py": [
    "7d0a8199890afb97894c363af7ef342b5ed5cef3",

--- a/testing/web-platform/meta/webdriver/tests/fullscreen_window.py.ini
+++ b/testing/web-platform/meta/webdriver/tests/fullscreen_window.py.ini
@@ -1,7 +1,3 @@
 [fullscreen_window.py]
   [test_handle_prompt_accept]
     expected: FAIL
-
-  [test_handle_prompt_missing_value]
-    expected: FAIL
-

--- a/testing/web-platform/tests/webdriver/tests/fullscreen_window.py
+++ b/testing/web-platform/tests/webdriver/tests/fullscreen_window.py
@@ -116,17 +116,17 @@ def test_handle_prompt_missing_value(ses
     """
     session.url = inline("<title>WD doc title</title>")
     create_dialog("alert", text="dismiss #1", result_var="dismiss1")
 
     response = fullscreen(session)
 
     assert_error(response, "unexpected alert open")
     assert_dialog_handled(session, "dismiss #1")
-    assert read_global(session, "accept1") == None
+    assert read_global(session, "dismiss1") == None
 
     create_dialog("confirm", text="dismiss #2", result_var="dismiss2")
 
     response = fullscreen(session)
 
     assert_error(response, "unexpected alert open")
     assert_dialog_handled(session, "dismiss #2")
     assert read_global(session, "dismiss2") == False