diff --git a/ihp-hsx/IHP/HSX/Parser.hs b/ihp-hsx/IHP/HSX/Parser.hs
index 2de14208f..1f50d1d5c 100644
--- a/ihp-hsx/IHP/HSX/Parser.hs
+++ b/ihp-hsx/IHP/HSX/Parser.hs
@@ -397,6 +397,7 @@ attributes = Set.fromList
         , "frameborder", "allow", "allowfullscreen", "nonce", "referrerpolicy", "slot"
         , "kind"
         , "html"
+        , "sse-connect", "sse-swap"
         ]
 
 parents :: Set Text