diff --git a/mjit.c b/mjit.c
index 80ab299039..3dc34e8f45 100644
--- a/mjit.c
+++ b/mjit.c
@@ -610,7 +610,7 @@ static const char *const CC_DLDFLAGS_ARGS[] = {
     MJIT_DLDFLAGS
 #if defined __GNUC__ && !defined __clang__
     "-nostartfiles",
-# ifndef _WIN32
+# if !defined(_WIN32) && !defined(__CYGWIN__)
     "-nodefaultlibs", "-nostdlib",
 # endif
 #endif
@@ -618,10 +618,12 @@ static const char *const CC_DLDFLAGS_ARGS[] = {
 };
 
 static const char *const CC_LIBS[] = {
-#ifdef _WIN32
+#if defined(_WIN32) || defined(__CYGWIN__)
     MJIT_LIBS
 # if defined __GNUC__ && !defined __clang__
+#  if defined(_WIN32)
     "-lmsvcrt",
+#  endif
     "-lgcc",
 # endif
 #endif
diff --git a/thread_pthread.c b/thread_pthread.c
index 6433849686..1a1a6fc0c6 100644
--- a/thread_pthread.c
+++ b/thread_pthread.c
@@ -1757,7 +1757,6 @@ rb_thread_create_mjit_thread(void (*child_hook)(void), void (*worker_func)(void)
 
     /* jit_worker thread is not to be joined */
     if (pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED) == 0
-        && pthread_attr_setscope(&attr, PTHREAD_SCOPE_SYSTEM) == 0
         && pthread_create(&worker_pid, &attr, mjit_worker, (void *)worker_func) == 0) {
         ret = TRUE;
     }