diff --git a/src/datastar_py/attributes.py b/src/datastar_py/attributes.py
index 0967fb0..40faa7b 100644
--- a/src/datastar_py/attributes.py
+++ b/src/datastar_py/attributes.py
@@ -642,6 +642,8 @@ def focus(self) -> Self:
 
 
 class OnIntersectAttr(BaseAttr, TimingMod, DelayMod, ViewtransitionMod):
+    _attr = "on-intersect"
+
     @property
     def once(self) -> Self:
         """Only trigger the event listener once."""