diff --git a/.changeset/rotten-lizards-remember.md b/.changeset/rotten-lizards-remember.md
new file mode 100644
index 000000000000..187f39f44731
--- /dev/null
+++ b/.changeset/rotten-lizards-remember.md
@@ -0,0 +1,5 @@
+---
+'svelte': patch
+---
+
+fix: reuse already attached attachments from spread attributes
diff --git a/packages/svelte/src/internal/client/dom/elements/attributes.js b/packages/svelte/src/internal/client/dom/elements/attributes.js
index 3d1acbd31ce1..407c3c69e725 100644
--- a/packages/svelte/src/internal/client/dom/elements/attributes.js
+++ b/packages/svelte/src/internal/client/dom/elements/attributes.js
@@ -448,7 +448,10 @@ export function set_attributes(element, prev, next, css_hash, skip_warning = fal
 	}
 
 	for (let symbol of Object.getOwnPropertySymbols(next)) {
-		if (symbol.description === ATTACHMENT_KEY) {
+		if (
+			symbol.description === ATTACHMENT_KEY &&
+			(prev == undefined || !(symbol in prev) || prev[symbol] !== next[symbol])
+		) {
 			attach(element, () => next[symbol]);
 		}
 	}