diff --git a/src/py/reactpy/tests/test_html.py b/src/py/reactpy/tests/test_html.py
index f16d1beed..334fcab03 100644
--- a/src/py/reactpy/tests/test_html.py
+++ b/src/py/reactpy/tests/test_html.py
@@ -122,6 +122,7 @@ def HasScript():
             """
         )
 
+        await poll(lambda: hasattr(incr_src_id, "current")).until_is(True)
         incr_src_id.current()
 
         run_count = await display.page.wait_for_selector("#run-count", state="attached")