diff --git a/include/mesos/mesos.proto b/include/mesos/mesos.proto
index d45ee5e..87132af 100644
--- a/include/mesos/mesos.proto
+++ b/include/mesos/mesos.proto
@@ -177,6 +177,10 @@
   repeated Attribute attributes = 5;
   optional SlaveID id = 6;
   optional bool checkpoint = 7 [default = false];
+
+  // Deprecated!
+  optional string webui_hostname = 2;
+  optional int32 webui_port = 4 [default = 8081];
 }
 
 
diff --git a/src/common/type_utils.hpp b/src/common/type_utils.hpp
index 90149d9..3b05751 100644
--- a/src/common/type_utils.hpp
+++ b/src/common/type_utils.hpp
@@ -281,6 +281,8 @@
 
 inline bool operator == (const SlaveInfo& left, const SlaveInfo& right)
 {
+  // NOTE: We don't compare 'webui_hostname' and 'webui_port' since
+  // they're deprecated and do not carry any semantic meaning.
   return left.hostname() == right.hostname() &&
     Resources(left.resources()) == Resources(right.resources()) &&
     internal::Attributes(left.attributes()) ==
diff --git a/src/slave/slave.cpp b/src/slave/slave.cpp
index 06ef786..ddf3710 100644
--- a/src/slave/slave.cpp
+++ b/src/slave/slave.cpp
@@ -234,6 +234,13 @@
   info.mutable_attributes()->MergeFrom(attributes);
   info.set_checkpoint(flags.checkpoint);
 
+  // The required 'webui_hostname' field has been deprecated and
+  // changed to optional for now, but we still need to set it for
+  // interoperating with code that expects it to be required (e.g., an
+  // executor on an older release).
+  // TODO(benh): Remove this after the deprecation cycle.
+  info.set_webui_hostname(hostname);
+
   // Spawn and initialize the isolator.
   // TODO(benh): Seems like the isolator should really be
   // spawned before being passed to the slave.