diff --git a/libc/private/bionic_globals.h b/libc/private/bionic_globals.h
index 447b3b9..d73079e 100644
--- a/libc/private/bionic_globals.h
+++ b/libc/private/bionic_globals.h
@@ -55,6 +55,9 @@
   // The malloc_dispatch_table is modified by malloc debug, malloc hooks,
   // and heaprofd. Only one of these modes can be active at any given time.
   _Atomic(const MallocDispatch*) current_dispatch_table;
+  // This pointer is only used by the allocation limit code when both a
+  // limit is enabled and some other hook is enabled at the same time.
+  _Atomic(const MallocDispatch*) default_dispatch_table;
   MallocDispatch malloc_dispatch_table;
 };
 
diff --git a/libc/private/bionic_malloc.h b/libc/private/bionic_malloc.h
index 5f4a75d..a1744aa 100644
--- a/libc/private/bionic_malloc.h
+++ b/libc/private/bionic_malloc.h
@@ -39,6 +39,12 @@
 #define M_INIT_ZYGOTE_CHILD_PROFILING M_INIT_ZYGOTE_CHILD_PROFILING
   M_RESET_HOOKS = 2,
 #define M_RESET_HOOKS M_RESET_HOOKS
+  // Set an upper bound on the total size in bytes of all allocations made
+  // using the memory allocation APIs.
+  //   arg = size_t*
+  //   arg_size = sizeof(size_t)
+  M_SET_ALLOCATION_LIMIT_BYTES = 3,
+#define M_SET_ALLOCATION_LIMIT_BYTES M_SET_ALLOCATION_LIMIT_BYTES
 };
 
 // Manipulates bionic-specific handling of memory allocation APIs such as