diff --git a/.changeset/metal-coats-thank.md b/.changeset/metal-coats-thank.md
new file mode 100644
index 0000000000..b307fd3d45
--- /dev/null
+++ b/.changeset/metal-coats-thank.md
@@ -0,0 +1,5 @@
+---
+"svelte": patch
+---
+
+fix: leave proxied array `length` untouched when deleting properties