diff --git a/src/datastar_py/attributes.py b/src/datastar_py/attributes.py
index 37b3b54..0279d72 100644
--- a/src/datastar_py/attributes.py
+++ b/src/datastar_py/attributes.py
@@ -408,7 +408,7 @@ class ViewtransitionMod:
     @property
     def viewtransition(self: Self) -> Self:
         """Wrap the expression in document.startViewTransition()."""
-        self._mods["view-transition"] = []
+        self._mods["viewtransition"] = []
         return self