diff --git a/include/ldap_pvt_thread.h b/include/ldap_pvt_thread.h
index c708315ed00db6c792ebb34f7f8f19e1591352c9..58cb7dd38bd16343956c3df703cfe0bfce43a080 100644
--- a/include/ldap_pvt_thread.h
+++ b/include/ldap_pvt_thread.h
@@ -43,7 +43,7 @@ ldap_pvt_thread_set_concurrency LDAP_P(( int ));
 
 #ifndef LDAP_PVT_THREAD_STACK_SIZE
 	/* LARGE stack */
-#define LDAP_PVT_THREAD_STACK_SIZE	(2*1024*1024)
+#define LDAP_PVT_THREAD_STACK_SIZE	(4*1024*1024)
 #endif
 
 LDAP_F( int )