Permission denied from too many threads on Windows.
diff --git a/tests/tcp_shutdown.c b/tests/tcp_shutdown.c
index 075c943..6637d67 100644
--- a/tests/tcp_shutdown.c
+++ b/tests/tcp_shutdown.c
@@ -37,6 +37,8 @@
 
 #ifdef NN_HAVE_WSL
 #define THREAD_COUNT 10
+#elif defined(NN_HAVE_WINDOWS)
+#define THREAD_COUNT 20
 #else
 #define THREAD_COUNT 100
 #endif