diff --git a/src/microhttpd/memorypool.c b/src/microhttpd/memorypool.c
index 1290408b..163aa4e3 100644
--- a/src/microhttpd/memorypool.c
+++ b/src/microhttpd/memorypool.c
@@ -77,6 +77,20 @@ struct MemoryPool
 };
 
 
+/**
+ * Free the memory given by @a ptr. Calls "free(ptr)".  This function
+ * should be used to free the username returned by
+ * #MHD_digest_auth_get_username().
+ *
+ * @param ptr pointer to free.
+ */
+void
+MHD_free (void *ptr)
+{
+  free (ptr);
+}
+
+
 /**
  * Create a memory pool.
  *