diff --git a/lib/topologies/mongos.js b/lib/topologies/mongos.js
index 90c0dee9c1..72fb3aa156 100644
--- a/lib/topologies/mongos.js
+++ b/lib/topologies/mongos.js
@@ -268,9 +268,9 @@ class Mongos extends TopologyBase {
       });
 
       // Set up listeners
-      self.s.coreTopology.once('timeout', errorHandler('timeout'));
-      self.s.coreTopology.once('error', errorHandler('error'));
-      self.s.coreTopology.once('close', errorHandler('close'));
+      self.s.coreTopology.on('timeout', errorHandler('timeout'));
+      self.s.coreTopology.on('error', errorHandler('error'));
+      self.s.coreTopology.on('close', errorHandler('close'));
 
       // Set up serverConfig listeners
       self.s.coreTopology.on('fullsetup', function() {