diff --git a/hermit/arch/x86/mm/page.c b/hermit/arch/x86/mm/page.c
index 9c415a620..c12db8919 100644
--- a/hermit/arch/x86/mm/page.c
+++ b/hermit/arch/x86/mm/page.c
@@ -173,7 +173,8 @@ out:
 
 int page_unmap(size_t viraddr, size_t npages)
 {
-	uint8_t ipi = 0;
+	if (BUILTIN_EXPECT(!npages, 0))
+		return 0;
 
 	spinlock_irqsave_lock(&page_lock);
 
@@ -183,11 +184,9 @@ int page_unmap(size_t viraddr, size_t npages)
 	for (vpn=start; vpn<start+npages; vpn++) {
 		self[0][vpn] = 0;
 		tlb_flush_one_page(vpn << PAGE_BITS, 0);
-		//ipi = 1;
 	}
 
-	if (ipi)
-		ipi_tlb_flush();
+	ipi_tlb_flush();
 
 	spinlock_irqsave_unlock(&page_lock);
 
diff --git a/hermit/mm/malloc.c b/hermit/mm/malloc.c
index 204a358d5..acd2ec4b3 100644
--- a/hermit/mm/malloc.c
+++ b/hermit/mm/malloc.c
@@ -223,11 +223,9 @@ int destroy_stack(void* viraddr, size_t sz)
 		return -ENOMEM;
 
 	// unmap and destroy stack
-	int8_t flag = irq_nested_disable();
 	vma_free((size_t)viraddr-PAGE_SIZE, (size_t)viraddr+(npages+1)*PAGE_SIZE);
 	page_unmap((size_t)viraddr, npages);
 	put_pages(phyaddr, npages);
-	irq_nested_enable(flag);
 
 	return 0;
 }