diff --git a/packages/svelte/src/reactivity/map.js b/packages/svelte/src/reactivity/map.js
index c581a2791406..5572a76d4277 100644
--- a/packages/svelte/src/reactivity/map.js
+++ b/packages/svelte/src/reactivity/map.js
@@ -105,7 +105,12 @@ export class SvelteMap extends Map {
 			increment(s);
 
 			// if not every reaction of s is a reaction of version we need to also include version
-			const needs_version_increase = !s.reactions?.every((r) => version.reactions?.includes(r));
+			var v_reactions = version.reactions === null ? null : new Set(version.reactions);
+			var needs_version_increase =
+				v_reactions === null ||
+				!s.reactions?.every((r) =>
+					/** @type {NonNullable<typeof v_reactions>} */ (v_reactions).has(r)
+				);
 			if (needs_version_increase) {
 				increment(version);
 			}