diff --git a/Python/thread.c b/Python/thread.c
index 87230e0..2298b38 100644
--- a/Python/thread.c
+++ b/Python/thread.c
@@ -98,6 +98,7 @@
 
 #ifdef HAVE_PTH
 #include "thread_pth.h"
+#undef _POSIX_THREADS
 #endif
 
 #ifdef _POSIX_THREADS
diff --git a/Python/thread_pth.h b/Python/thread_pth.h
index 3b97981..8c7dbe9 100644
--- a/Python/thread_pth.h
+++ b/Python/thread_pth.h
@@ -30,6 +30,8 @@
 
 #define CHECK_STATUS(name)  if (status == -1) { printf("%d ", status); perror(name); error = 1; }
 
+pth_attr_t PyThread_attr;
+
 /*
  * Initialization.
  */
@@ -37,6 +39,9 @@
 static void PyThread__init_thread(void)
 {
 	pth_init();
+	PyThread_attr = pth_attr_new();
+	pth_attr_set(PyThread_attr, PTH_ATTR_STACK_SIZE, 1<<18);
+	pth_attr_set(PyThread_attr, PTH_ATTR_JOINABLE, FALSE);
 }
 
 /*
@@ -51,7 +56,7 @@
 	if (!initialized)
 		PyThread_init_thread();
 
-	th = pth_spawn(PTH_ATTR_DEFAULT,
+	th = pth_spawn(PyThread_attr,
 				 (void* (*)(void *))func,
 				 (void *)arg
 				 );