diff --git a/Tests/AcmeSwiftTests/AccountTests.swift b/Tests/AcmeSwiftTests/AccountTests.swift
index 25b8df2..93484e2 100644
--- a/Tests/AcmeSwiftTests/AccountTests.swift
+++ b/Tests/AcmeSwiftTests/AccountTests.swift
@@ -13,7 +13,7 @@ final class AccountTests: XCTestCase {
         self.logger = Logger.init(label: "acme-swift-tests")
         self.logger.logLevel = .trace
         
-        var config = HTTPClient.Configuration(certificateVerification: .fullVerification, backgroundActivityLogger: self.logger)
+        let config = HTTPClient.Configuration(certificateVerification: .fullVerification, backgroundActivityLogger: self.logger)
         self.http = HTTPClient(
             eventLoopGroupProvider: .singleton,
             configuration: config