diff --git a/include/ircd/ios.h b/include/ircd/ios.h
index 5735e0f73..467ee5cea 100644
--- a/include/ircd/ios.h
+++ b/include/ircd/ios.h
@@ -70,6 +70,9 @@ struct ircd::ios::descriptor
 {
 	static uint64_t ids;
 
+	static void *default_allocator(handler &, const size_t &);
+	static void default_deallocator(handler &, void *const &, const size_t &);
+
 	string_view name;
 	uint64_t id {++ids};
 	uint64_t calls {0};
@@ -81,7 +84,13 @@ struct ircd::ios::descriptor
 	uint64_t slice_total {0};
 	uint64_t slice_last {0};
 
-	descriptor(const string_view &name);
+	std::function<void *(handler &, const size_t &)> allocator;
+	std::function<void (handler &, void *const &, const size_t &)> deallocator;
+
+	descriptor(const string_view &name,
+	           const decltype(allocator) & = default_allocator,
+	           const decltype(deallocator) & = default_deallocator);
+
 	descriptor(descriptor &&) = delete;
 	descriptor(const descriptor &) = delete;
 	~descriptor() noexcept;
diff --git a/ircd/ios.cc b/ircd/ios.cc
index 602bcc452..50392f99d 100644
--- a/ircd/ios.cc
+++ b/ircd/ios.cc
@@ -124,9 +124,15 @@ ircd::ios::descriptor::ids;
 // descriptor::descriptor
 //
 
-ircd::ios::descriptor::descriptor(const string_view &name)
+ircd::ios::descriptor::descriptor(const string_view &name,
+                                  const decltype(allocator) &allocator,
+                                  const decltype(deallocator) &deallocator)
 :name{name}
+,allocator{allocator}
+,deallocator{deallocator}
 {
+	assert(allocator);
+	assert(deallocator);
 }
 
 ircd::ios::descriptor::~descriptor()
@@ -134,6 +140,21 @@ noexcept
 {
 }
 
+void
+ircd::ios::descriptor::default_deallocator(handler &handler,
+                                           void *const &ptr,
+                                           const size_t &size)
+{
+	::operator delete(ptr, size);
+}
+
+void *
+ircd::ios::descriptor::default_allocator(handler &handler,
+                                         const size_t &size)
+{
+	return ::operator new(size);
+}
+
 //
 // handler
 //
@@ -189,7 +210,7 @@ ircd::ios::handler::deallocate(handler *const &handler,
 {
 	assert(handler && handler->descriptor);
 	auto &descriptor(*handler->descriptor);
-	::operator delete(ptr, size);
+	descriptor.deallocator(*handler, ptr, size);
 	descriptor.free_bytes += size;
 	++descriptor.frees;
 }
@@ -202,5 +223,5 @@ ircd::ios::handler::allocate(handler *const &handler,
 	auto &descriptor(*handler->descriptor);
 	descriptor.alloc_bytes += size;
 	++descriptor.allocs;
-	return ::operator new(size);
+	return descriptor.allocator(*handler, size);
 }