diff --git a/src/functional_tests/test_room_sea_select.py b/src/functional_tests/test_room_sea_select.py
index 5859374..c612290 100644
--- a/src/functional_tests/test_room_sea_select.py
+++ b/src/functional_tests/test_room_sea_select.py
@@ -132,12 +132,21 @@ class PickSeaAsyncTransitionTest(ChannelsFunctionalTest):
         self.wait_for(lambda: self.browser.find_element(By.ID, "id_pick_sky_btn"))
 
         self._confirm_sky()
-        pick_sea = self.wait_for(lambda: self.browser.find_element(By.ID, "id_pick_sea_btn"))
-        self.browser.execute_script("arguments[0].click()", pick_sea)
+        self.wait_for(lambda: self.browser.find_element(By.ID, "id_pick_sea_btn"))
 
-        sea_overlay = self.wait_for(
-            lambda: self.browser.find_element(By.ID, "id_sea_overlay")
-        )
+        # On slow CI, the PICK SEA btn parses into the DOM before the inline
+        # `<script>` at the bottom of _sea_overlay.html has bound `openSea` to
+        # it; a one-shot click can land before the handler exists. Retry click
+        # + assert together via wait_for so the race resolves naturally.
+        def _click_and_assert_sea_open():
+            btn = self.browser.find_element(By.ID, "id_pick_sea_btn")
+            self.browser.execute_script("arguments[0].click()", btn)
+            self.assertTrue(self.browser.execute_script(
+                "return document.documentElement.classList.contains('sea-open')"
+            ))
+        self.wait_for(_click_and_assert_sea_open)
+
+        sea_overlay = self.browser.find_element(By.ID, "id_sea_overlay")
         self.assertTrue(sea_overlay.is_displayed())