diff --git a/src/rendering/hyperscript_integration.jl b/src/rendering/hyperscript_integration.jl
index 53ffe606..1dd12e64 100644
--- a/src/rendering/hyperscript_integration.jl
+++ b/src/rendering/hyperscript_integration.jl
@@ -111,7 +111,7 @@ function attribute_render(session::Session, parent, attribute::String, jss::JSCo
     return ""
 end
 
-function attribute_render(session::Session, parent, attribute::String, asset::Union{Link, Asset})
+function attribute_render(session::Session, parent, ::String, asset::AbstractAsset)
     if parent isa Hyperscript.Node{Hyperscript.CSS}
         # css seems to require an url object
         return "url($(url(session, asset)))"