diff --git a/src/allmydata/mutable/servermap.py b/src/allmydata/mutable/servermap.py
index 474779a1f..f0b4d3520 100644
--- a/src/allmydata/mutable/servermap.py
+++ b/src/allmydata/mutable/servermap.py
@@ -434,7 +434,7 @@ class ServermapUpdater:
         if k is None:
             # make a guess
             k = 3
-        N = self._node.get_required_shares()
+        N = self._node.get_total_shares()
         if N is None:
             N = 10
         self.EPSILON = k