diff --git a/test/runtime/samples/bitmask-overflow/_config.js b/test/runtime/samples/bitmask-overflow/_config.js
index 7d550da056..7e9ad4d33b 100644
--- a/test/runtime/samples/bitmask-overflow/_config.js
+++ b/test/runtime/samples/bitmask-overflow/_config.js
@@ -44,6 +44,8 @@ export default {
 	`,
 
 	test({ assert, component, target }) {
+		component.reads = {};
+
 		component._0 = 'a';
 		component._30 = 'b';
 		component._31 = 'c';
@@ -93,5 +95,13 @@ export default {
 			<p>39</p>
 			<p>e</p>
 		`);
+
+		assert.deepEqual(component.reads, {
+			_0: 1,
+			_30: 1,
+			_31: 1,
+			_32: 1,
+			_40: 1
+		});
 	}
 };
\ No newline at end of file
diff --git a/test/runtime/samples/bitmask-overflow/main.svelte b/test/runtime/samples/bitmask-overflow/main.svelte
index 20216786c2..c40c45e749 100644
--- a/test/runtime/samples/bitmask-overflow/main.svelte
+++ b/test/runtime/samples/bitmask-overflow/main.svelte
@@ -1,4 +1,6 @@
 <script>
+	export let reads = {};
+
 	export let _0 = '0';
 	export let _1 = '1';
 	export let _2 = '2';
@@ -40,46 +42,53 @@
 	export let _38 = '38';
 	export let _39 = '39';
 	export let _40 = '40';
+
+	const read = (value, label) => {
+		if (!reads[label]) reads[label] = 0;
+		reads[label] += 1;
+
+		return value;
+	};
 </script>
 
-<p>{_0}</p>
-<p>{_1}</p>
-<p>{_2}</p>
-<p>{_3}</p>
-<p>{_4}</p>
-<p>{_5}</p>
-<p>{_6}</p>
-<p>{_7}</p>
-<p>{_8}</p>
-<p>{_9}</p>
-<p>{_10}</p>
-<p>{_11}</p>
-<p>{_12}</p>
-<p>{_13}</p>
-<p>{_14}</p>
-<p>{_15}</p>
-<p>{_16}</p>
-<p>{_17}</p>
-<p>{_18}</p>
-<p>{_19}</p>
-<p>{_20}</p>
-<p>{_21}</p>
-<p>{_22}</p>
-<p>{_23}</p>
-<p>{_24}</p>
-<p>{_25}</p>
-<p>{_26}</p>
-<p>{_27}</p>
-<p>{_28}</p>
-<p>{_29}</p>
-<p>{_30}</p>
-<p>{_31}</p>
-<p>{_32}</p>
-<p>{_33}</p>
-<p>{_34}</p>
-<p>{_35}</p>
-<p>{_36}</p>
-<p>{_37}</p>
-<p>{_38}</p>
-<p>{_39}</p>
-<p>{_40}</p>
\ No newline at end of file
+<p>{read(_0, '_0')}</p>
+<p>{read(_1, '_1')}</p>
+<p>{read(_2, '_2')}</p>
+<p>{read(_3, '_3')}</p>
+<p>{read(_4, '_4')}</p>
+<p>{read(_5, '_5')}</p>
+<p>{read(_6, '_6')}</p>
+<p>{read(_7, '_7')}</p>
+<p>{read(_8, '_8')}</p>
+<p>{read(_9, '_9')}</p>
+<p>{read(_10, '_10')}</p>
+<p>{read(_11, '_11')}</p>
+<p>{read(_12, '_12')}</p>
+<p>{read(_13, '_13')}</p>
+<p>{read(_14, '_14')}</p>
+<p>{read(_15, '_15')}</p>
+<p>{read(_16, '_16')}</p>
+<p>{read(_17, '_17')}</p>
+<p>{read(_18, '_18')}</p>
+<p>{read(_19, '_19')}</p>
+<p>{read(_20, '_20')}</p>
+<p>{read(_21, '_21')}</p>
+<p>{read(_22, '_22')}</p>
+<p>{read(_23, '_23')}</p>
+<p>{read(_24, '_24')}</p>
+<p>{read(_25, '_25')}</p>
+<p>{read(_26, '_26')}</p>
+<p>{read(_27, '_27')}</p>
+<p>{read(_28, '_28')}</p>
+<p>{read(_29, '_29')}</p>
+<p>{read(_30, '_30')}</p>
+<p>{read(_31, '_31')}</p>
+<p>{read(_32, '_32')}</p>
+<p>{read(_33, '_33')}</p>
+<p>{read(_34, '_34')}</p>
+<p>{read(_35, '_35')}</p>
+<p>{read(_36, '_36')}</p>
+<p>{read(_37, '_37')}</p>
+<p>{read(_38, '_38')}</p>
+<p>{read(_39, '_39')}</p>
+<p>{read(_40, '_40')}</p>
\ No newline at end of file