diff --git a/lib/swift/Sources/TSocketServer.swift b/lib/swift/Sources/TSocketServer.swift
index 6cfb5a1..5d0dd49 100644
--- a/lib/swift/Sources/TSocketServer.swift
+++ b/lib/swift/Sources/TSocketServer.swift
@@ -56,7 +56,7 @@
       let sock = CFSocketCreate(kCFAllocatorDefault, PF_INET, SOCK_STREAM, IPPROTO_TCP, 0, nil, nil)
     #endif
     if sock != nil {
-      CFSocketSetSocketFlags(sock, CFSocketGetSocketFlags(sock) & ~kCFSocketCloseOnInvalidate)
+      CFSocketSetSocketFlags(sock, CFSocketGetSocketFlags(sock) & ~CFOptionFlags(kCFSocketCloseOnInvalidate))
 
       fd = CFSocketGetNative(sock)
       var yes = 1