diff --git a/client/app/scripts/components/topology-options.js b/client/app/scripts/components/topology-options.js
index c4276c28e..bc7a153c0 100644
--- a/client/app/scripts/components/topology-options.js
+++ b/client/app/scripts/components/topology-options.js
@@ -1,5 +1,7 @@
 import React from 'react';
 import { connect } from 'react-redux';
+import { Map as makeMap } from 'immutable';
+import includes from 'lodash/includes';
 
 import { getCurrentTopologyOptions } from '../utils/topology-utils';
 import { activeTopologyOptionsSelector } from '../selectors/topology';
@@ -11,19 +13,37 @@ class TopologyOptions extends React.Component {
     super(props, context);
 
     this.handleOptionClick = this.handleOptionClick.bind(this);
+    this.handleNoneClick = this.handleNoneClick.bind(this);
   }
 
   handleOptionClick(optionId, value, topologyId) {
+    let nextOptions = [value];
     const { activeOptions, options } = this.props;
     const selectedOption = options.find(o => o.get('id') === optionId);
 
     if (selectedOption.get('selectType') === 'union') {
-      const isSelectedAlready = activeOptions.get(selectedOption.get('id')).includes(value);
-      const addOrRemove = isSelectedAlready ? 'remove' : 'add';
-      this.props.changeTopologyOption(optionId, value, topologyId, addOrRemove);
-    } else {
-      this.props.changeTopologyOption(optionId, value, topologyId);
+      // Multi-select topology options (such as k8s namespaces) are handled here.
+      // Users can select one, many, or none of these options.
+      // The component builds an array of the next selected values that are sent to the action.
+      const opts = activeOptions.toJS();
+      const selected = selectedOption.get('id');
+      const isSelectedAlready = includes(opts[selected], value);
+
+      if (isSelectedAlready) {
+        // Remove the option if it is already selected
+        nextOptions = opts[selected].filter(o => o !== value);
+      } else {
+        // Add it to the array if it's not selected
+        nextOptions = opts[selected].concat(value);
+      }
+      // Since the user is clicking an option, remove the highlighting from the 'none' option.
+      nextOptions = nextOptions.filter(o => o !== 'none');
     }
+    this.props.changeTopologyOption(optionId, nextOptions, topologyId);
+  }
+
+  handleNoneClick(optionId, value, topologyId) {
+    this.props.changeTopologyOption(optionId, ['none'], topologyId);
   }
 
   renderOption(option) {
@@ -32,7 +52,10 @@ class TopologyOptions extends React.Component {
     const activeValue = activeOptions && activeOptions.has(optionId)
       ? activeOptions.get(optionId)
       : option.get('defaultValue');
-
+    const noneItem = makeMap({
+      value: 'none',
+      label: option.get('noneLabel')
+    });
     return (
       <div className="topology-option" key={optionId}>
         <div className="topology-option-wrapper">
@@ -46,6 +69,15 @@ class TopologyOptions extends React.Component {
               item={item}
             />
           ))}
+          {option.get('selectType') === 'union' &&
+            <TopologyOptionAction
+              onClick={this.handleNoneClick}
+              optionId={optionId}
+              item={noneItem}
+              topologyId={topologyId}
+              activeValue={activeValue}
+            />
+          }
         </div>
       </div>
     );
diff --git a/client/app/scripts/reducers/__tests__/root-test.js b/client/app/scripts/reducers/__tests__/root-test.js
index ec7993be7..45f46daee 100644
--- a/client/app/scripts/reducers/__tests__/root-test.js
+++ b/client/app/scripts/reducers/__tests__/root-test.js
@@ -167,14 +167,14 @@ describe('RootReducer', () => {
     type: ActionTypes.CHANGE_TOPOLOGY_OPTION,
     topologyId: 'topo1',
     option: 'option1',
-    value: 'on'
+    value: ['on']
   };
 
   const ChangeTopologyOptionAction2 = {
     type: ActionTypes.CHANGE_TOPOLOGY_OPTION,
     topologyId: 'topo1',
     option: 'option1',
-    value: 'off'
+    value: ['off']
   };
 
   const ClickNodeAction = {
@@ -371,15 +371,13 @@ describe('RootReducer', () => {
       type: ActionTypes.CHANGE_TOPOLOGY_OPTION,
       topologyId: 'services',
       option: 'namespace',
-      value: 'scope',
-      addOrRemove: 'add'
+      value: ['default', 'scope'],
     };
     const removeAction = {
       type: ActionTypes.CHANGE_TOPOLOGY_OPTION,
       topologyId: 'services',
       option: 'namespace',
-      value: 'scope',
-      addOrRemove: 'remove'
+      value: ['default']
     };
     let nextState = initialState;
     nextState = reducer(nextState, { type: ActionTypes.RECEIVE_TOPOLOGIES, topologies});
diff --git a/client/app/scripts/reducers/root.js b/client/app/scripts/reducers/root.js
index 3e673e837..199645ea4 100644
--- a/client/app/scripts/reducers/root.js
+++ b/client/app/scripts/reducers/root.js
@@ -194,7 +194,6 @@ export function rootReducer(state = initialState, action) {
       // set option on parent topology
       const topology = findTopologyById(state.get('topologies'), action.topologyId);
       if (topology) {
-        let values = [action.value];
         const topologyId = topology.get('parentId') || topology.get('id');
         const optionKey = ['topologyOptions', topologyId, action.option];
         const currentOption = state.getIn(['topologyOptions', topologyId, action.option]);
@@ -203,12 +202,7 @@ export function rootReducer(state = initialState, action) {
           state = clearNodes(state);
         }
 
-        if (action.addOrRemove === 'add') {
-          values = state.getIn(optionKey).concat(values);
-        } else if (action.addOrRemove === 'remove') {
-          values = state.getIn(optionKey).filter(o => !values.includes(o));
-        }
-        state = state.setIn(optionKey, values);
+        state = state.setIn(optionKey, action.value);
       }
       return state;
     }