diff --git a/libc/include/malloc.h b/libc/include/malloc.h
index ba0af3c..833fa59 100644
--- a/libc/include/malloc.h
+++ b/libc/include/malloc.h
@@ -170,6 +170,28 @@
  * Available since API level 28.
  */
 #define M_PURGE (-101)
+/**
+ * mallopt() option to set the maximum number of items in the secondary
+ * cache of the scudo allocator.
+ *
+ * Available since API level 31.
+ */
+#define M_CACHE_COUNT_MAX (-200)
+/**
+ * mallopt() option to set the maximum size in bytes of a cacheable item in
+ * the secondary cache of the scudo allocator.
+ *
+ * Available since API level 31.
+ */
+#define M_CACHE_SIZE_MAX (-201)
+/**
+ * mallopt() option to increase the maximum number of shared thread-specific
+ * data structures that can be created. This number cannot be decreased,
+ * only increased and only applies to the scudo allocator.
+ *
+ * Available since API level 31.
+ */
+#define M_TSDS_COUNT_MAX (-202)
 
 /**
  * [mallopt(3)](http://man7.org/linux/man-pages/man3/mallopt.3.html) modifies