diff --git a/libc/bionic/jemalloc_wrapper.cpp b/libc/bionic/jemalloc_wrapper.cpp
index 812884c..40f2a66 100644
--- a/libc/bionic/jemalloc_wrapper.cpp
+++ b/libc/bionic/jemalloc_wrapper.cpp
@@ -79,6 +79,18 @@
       }
     }
     return 1;
+  } else if (param == M_PURGE) {
+    unsigned narenas;
+    size_t sz = sizeof(unsigned);
+    if (je_mallctl("arenas.narenas", &narenas, &sz, nullptr, 0) != 0) {
+      return 0;
+    }
+    char buffer[100];
+    snprintf(buffer, sizeof(buffer), "arena.%u.purge", narenas);
+    if (je_mallctl(buffer, nullptr, nullptr, nullptr, 0) != 0) {
+      return 0;
+    }
+    return 1;
   }
   return 0;
 }
diff --git a/libc/include/malloc.h b/libc/include/malloc.h
index f5fbedf..58a9b1d 100644
--- a/libc/include/malloc.h
+++ b/libc/include/malloc.h
@@ -163,6 +163,7 @@
 
 /** mallopt() option to set the decay time. Valid values are 0 and 1. */
 #define M_DECAY_TIME -100
+#define M_PURGE -101
 
 /**
  * [mallopt(3)](http://man7.org/linux/man-pages/man3/mallopt.3.html) modifies