diff --git a/Tests/SioEffectsTests/CancellationTests.swift b/Tests/SioEffectsTests/CancellationTests.swift
index 595318c..e5cddf4 100644
--- a/Tests/SioEffectsTests/CancellationTests.swift
+++ b/Tests/SioEffectsTests/CancellationTests.swift
@@ -15,7 +15,7 @@ class CancellationTests: XCTestCase {
 	let scheduler = TestScheduler()
 	
 	func testNoCancellation() {
-		let lastValue: Int = 0
+		var lastValue: Int = 0
 		var task: UIO<Void>?
 		
 		let finish = expectation(description: "finish")