diff --git a/.changeset/cuddly-owls-smile.md b/.changeset/cuddly-owls-smile.md
new file mode 100644
index 0000000000..cdd71449ae
--- /dev/null
+++ b/.changeset/cuddly-owls-smile.md
@@ -0,0 +1,5 @@
+---
+'svelte': patch
+---
+
+fix: unmount not deferred components immediately
diff --git a/packages/svelte/src/internal/client/dom/blocks/svelte-component.js b/packages/svelte/src/internal/client/dom/blocks/svelte-component.js
index be6611c96d..77b1834334 100644
--- a/packages/svelte/src/internal/client/dom/blocks/svelte-component.js
+++ b/packages/svelte/src/internal/client/dom/blocks/svelte-component.js
@@ -51,7 +51,8 @@ export function component(node, get_component, render_fn) {
 
 		var defer = should_defer_append();
 
-		if (effect) {
+		// For sync context: immediately pause the old effect
+		if (!defer && effect) {
 			pause_effect(effect);
 			effect = null;
 		}