diff --git a/Tests/LanguageServerProtocolJSONRPCTests/ConnectionTests.swift b/Tests/LanguageServerProtocolJSONRPCTests/ConnectionTests.swift
index e78654a1..d0c1e8e5 100644
--- a/Tests/LanguageServerProtocolJSONRPCTests/ConnectionTests.swift
+++ b/Tests/LanguageServerProtocolJSONRPCTests/ConnectionTests.swift
@@ -264,7 +264,7 @@ class ConnectionTests: XCTestCase {
       to.fileHandleForWriting.closeFile()
 #if os(Windows)
       // 1 ms was chosen for simplicity.
-      _ = Sleep(1)
+      Sleep(1)
 #else
       // 100 us was chosen empirically to encourage races.
       usleep(100)