diff --git a/repos/base-nova/ports/nova.hash b/repos/base-nova/ports/nova.hash
index ef9ca4684..df828aff1 100644
--- a/repos/base-nova/ports/nova.hash
+++ b/repos/base-nova/ports/nova.hash
@@ -1 +1 @@
-0cdaf637a3a1c087b6350142316230c9e963a8d7
+001f770ae2ae32c6f43e295355021065f4a28ee5
diff --git a/repos/base-nova/ports/nova.port b/repos/base-nova/ports/nova.port
index f703bc7b2..c583f0817 100644
--- a/repos/base-nova/ports/nova.port
+++ b/repos/base-nova/ports/nova.port
@@ -4,7 +4,7 @@ DOWNLOADS := nova.git
 
 # r9 branch - use r9_debug for more verbose kernel messages
 URL(nova) := https://github.com/alex-ab/NOVA.git
-REV(nova) := 12032f96fd3f09c248cad9d76527d4b3ac087fef
+REV(nova) := c852537f73209f9d9d4d2bec50e01d8fec76214e
 DIR(nova) := src/kernel/nova
 
 PATCHES   := $(wildcard $(REP_DIR)/patches/*.patch)
diff --git a/repos/base-nova/src/core/platform_pd.cc b/repos/base-nova/src/core/platform_pd.cc
index 97b5b1e17..07889ef5b 100644
--- a/repos/base-nova/src/core/platform_pd.cc
+++ b/repos/base-nova/src/core/platform_pd.cc
@@ -51,7 +51,7 @@ int Platform_pd::assign_parent(Native_capability parent)
 
 Platform_pd::Platform_pd(Allocator * md_alloc, char const *,
                          signed pd_id, bool create)
-: _thread_cnt(0), _pd_sel(~0UL) { }
+: _thread_cnt(0), _pd_sel(Native_thread::INVALID_INDEX) { }
 
 
 Platform_pd::~Platform_pd()
@@ -59,7 +59,8 @@ Platform_pd::~Platform_pd()
 	/* invalidate weak pointers to this object */
 	Address_space::lock_for_destruction();
 
-	if (_pd_sel == ~0UL) return;
+	if (_pd_sel == Native_thread::INVALID_INDEX)
+		return;
 
 	/* Revoke and free cap, pd is gone */
 	Nova::revoke(Nova::Obj_crd(_pd_sel, 0));
@@ -74,6 +75,9 @@ void Platform_pd::flush(addr_t remote_virt, size_t size)
 	Flexpage_iterator flex(remote_virt, size, remote_virt, size, 0);
 	Flexpage page = flex.page();
 
+	if (pd_sel() == Native_thread::INVALID_INDEX)
+		return;
+
 	while (page.valid()) {
 		Nova::Mem_crd mem(page.addr >> 12, page.log2_order - 12, revoke_rwx);
 		Nova::revoke(mem, true, true, pd_sel());
diff --git a/repos/base-nova/src/core/platform_thread.cc b/repos/base-nova/src/core/platform_thread.cc
index 509724d82..d17a9d1a0 100644
--- a/repos/base-nova/src/core/platform_thread.cc
+++ b/repos/base-nova/src/core/platform_thread.cc
@@ -89,7 +89,7 @@ int Platform_thread::start(void *ip, void *sp)
 			res = create_ec(_sel_ec(), _pd->pd_sel(), _location.xpos(),
 			                utcb, initial_sp, _sel_exc_base, thread_global);
 			if (res == Nova::NOVA_PD_OOM && Nova::NOVA_OK != _pager->handle_oom()) {
-				_pd->assign_pd(Native_thread::INVALID_INDEX);
+				_pager->assign_pd(Native_thread::INVALID_INDEX);
 				PERR("creation of new thread failed %u", res);
 				return -4;
 			}
diff --git a/repos/base-nova/src/kernel/target.mk b/repos/base-nova/src/kernel/target.mk
index 47d84ecd6..1e1d95de1 100644
--- a/repos/base-nova/src/kernel/target.mk
+++ b/repos/base-nova/src/kernel/target.mk
@@ -25,7 +25,7 @@ CC_WARN         += -Wframe-larger-than=64
 CC_OPT          += -mpreferred-stack-boundary=2 -mregparm=3
 else
 ifeq ($(filter-out $(SPECS),64bit),)
-CC_WARN         += -Wframe-larger-than=128
+CC_WARN         += -Wframe-larger-than=144
 CC_OPT          += -mpreferred-stack-boundary=4 -mcmodel=kernel -mno-red-zone
 else
 $(error Unsupported environment)