diff --git a/Python/hamt.c b/Python/hamt.c
index 5217122..f8bce59 100644
--- a/Python/hamt.c
+++ b/Python/hamt.c
@@ -2476,6 +2476,8 @@
     if (o == NULL) {
         return NULL;
     }
+    o->h_count = 0;
+    o->h_root = NULL;
     o->h_weakreflist = NULL;
     PyObject_GC_Track(o);
     return o;