diff --git a/components/style/properties/longhands/box.mako.rs b/components/style/properties/longhands/box.mako.rs
index a5c3b38b34d..bddc56da848 100644
--- a/components/style/properties/longhands/box.mako.rs
+++ b/components/style/properties/longhands/box.mako.rs
@@ -413,7 +413,7 @@ ${helpers.predefined_type(
     "LengthPercentage",
     "computed::LengthPercentage::zero()",
     products="gecko",
-    animation_value_type="none",
+    animation_value_type="ComputedValue",
     gecko_pref="layout.css.motion-path.enabled",
     spec="https://drafts.fxtf.org/motion-1/#offset-distance-property",
     servo_restyle_damage="reflow_out_of_flow"