diff --git a/libc/bionic/malloc_common.cpp b/libc/bionic/malloc_common.cpp
index 0ee12a7..955cf18 100644
--- a/libc/bionic/malloc_common.cpp
+++ b/libc/bionic/malloc_common.cpp
@@ -102,6 +102,15 @@
 }
 
 extern "C" int mallopt(int param, int value) {
+  // Some are handled by libc directly rather than by the allocator.
+  if (param == M_BIONIC_SET_HEAP_TAGGING_LEVEL) {
+    ScopedPthreadMutexLocker locker(&g_heap_tagging_lock);
+    return SetHeapTaggingLevel(static_cast<HeapTaggingLevel>(value));
+  }
+  if (param == M_BIONIC_DISABLE_MEMORY_MITIGATIONS) {
+    return DisableMemoryMitigations(value);
+  }
+  // The rest we pass on...
   auto dispatch_table = GetDispatchTable();
   if (__predict_false(dispatch_table != nullptr)) {
     return dispatch_table->mallopt(param, value);
@@ -316,9 +325,8 @@
   if (opcode == M_SET_ALLOCATION_LIMIT_BYTES) {
     return LimitEnable(arg, arg_size);
   }
-  if (opcode == M_SET_HEAP_TAGGING_LEVEL) {
-    ScopedPthreadMutexLocker locker(&g_heap_tagging_lock);
-    return SetHeapTaggingLevel(arg, arg_size);
+  if (opcode == M_SET_HEAP_TAGGING_LEVEL && arg_size == sizeof(HeapTaggingLevel)) {
+    return mallopt(M_BIONIC_SET_HEAP_TAGGING_LEVEL, *reinterpret_cast<HeapTaggingLevel*>(arg));
   }
   if (opcode == M_INITIALIZE_GWP_ASAN) {
     if (arg == nullptr || arg_size != sizeof(bool)) {
@@ -329,8 +337,8 @@
       return MaybeInitGwpAsan(globals, *reinterpret_cast<bool*>(arg));
     });
   }
-  if (opcode == M_DISABLE_MEMORY_MITIGATIONS) {
-    return DisableMemoryMitigations(arg, arg_size);
+  if (opcode == M_DISABLE_MEMORY_MITIGATIONS && arg_size == sizeof(int)) {
+    return mallopt(M_BIONIC_DISABLE_MEMORY_MITIGATIONS, reinterpret_cast<intptr_t>(arg));
   }
   errno = ENOTSUP;
   return false;