diff --git a/src/components/structures/LeftPanel.js b/src/components/structures/LeftPanel.js
index b48d03be..60f07a62 100644
--- a/src/components/structures/LeftPanel.js
+++ b/src/components/structures/LeftPanel.js
@@ -19,6 +19,7 @@ limitations under the License.
 import React from 'react';
 import { DragDropContext } from 'react-dnd';
 import HTML5Backend from 'react-dnd-html5-backend';
+import classNames from 'classnames';
 import KeyCode from 'matrix-react-sdk/lib/KeyCode';
 import sdk from 'matrix-react-sdk';
 import dis from 'matrix-react-sdk/lib/dispatcher';
@@ -55,7 +56,7 @@ var LeftPanel = React.createClass({
         // We just need to update if any of these things change.
         if (
             this.props.collapsed !== nextProps.collapsed ||
-            this.props.opacity !== nextProps.opacity
+            this.props.disabled !== nextProps.disabled
         ) {
             return true;
         }
@@ -176,21 +177,16 @@ var LeftPanel = React.createClass({
             topBox = <SearchBox collapsed={ this.props.collapsed } onSearch={ this.onSearch } />;
         }
 
-        let classes = "mx_LeftPanel mx_fadable";
-        if (this.props.collapsed) {
-            classes += " collapsed";
-        }
+        let classes = classNames(
+            "mx_LeftPanel", "mx_fadable",
+            {
+                "collapsed": this.props.collapsed,
+                "mx_fadable_faded": this.props.disabled,
+            }
+        );
 
         return (
-            <aside className={classes}
-                style={{
-                    opacity: this.props.opacity,
-                    pointerEvents: this.props.opacity < 1.0 ? 'none' : undefined,
-                }}
-                onKeyDown={ this._onKeyDown }
-                onFocus={ this._onFocus }
-                onBlur={ this._onBlur }
-            >
+            <aside className={classes} onKeyDown={ this._onKeyDown } onFocus={ this._onFocus } onBlur={ this._onBlur }>
                 { topBox }
                 <CallPreview ConferenceHandler={VectorConferenceHandler} />
                 <RoomList
diff --git a/src/components/structures/RightPanel.js b/src/components/structures/RightPanel.js
index c32c0646..6b025ac9 100644
--- a/src/components/structures/RightPanel.js
+++ b/src/components/structures/RightPanel.js
@@ -18,6 +18,7 @@ limitations under the License.
 
 import React from 'react';
 import PropTypes from 'prop-types';
+import classNames from 'classnames';
 import { _t } from 'matrix-react-sdk/lib/languageHandler';
 import sdk from 'matrix-react-sdk';
 import dis from 'matrix-react-sdk/lib/dispatcher';
@@ -345,18 +346,16 @@ module.exports = React.createClass({
             );
         }
 
-        let classes = "mx_RightPanel mx_fadable";
-        if (this.props.collapsed) {
-            classes += " collapsed";
-        }
+        let classes = classNames(
+            "mx_RightPanel", "mx_fadable",
+            {
+                "collapsed": this.props.collapsed,
+                "mx_fadable_faded": this.props.disabled,
+            }
+        );
 
         return (
-            <aside className={classes}
-                style={{
-                    opacity: this.props.opacity,
-                    pointerEvents: this.props.opacity < 1.0 ? 'none' : undefined,
-                }}
-            >
+            <aside className={classes}>
                 <div className="mx_RightPanel_header">
                     <div className="mx_RightPanel_headerButtonGroup">
                         {headerButtons}
diff --git a/src/components/structures/RoomDirectory.js b/src/components/structures/RoomDirectory.js
index cd9ac565..323af86c 100644
--- a/src/components/structures/RoomDirectory.js
+++ b/src/components/structures/RoomDirectory.js
@@ -89,17 +89,17 @@ module.exports = React.createClass({
         });
 
         // dis.dispatch({
-        //     action: 'ui_opacity',
-        //     sideOpacity: 0.3,
-        //     middleOpacity: 0.3,
+        //     action: 'panel_disable',
+        //     sideDisabled: true,
+        //     middleDisabled: true,
         // });
     },
 
     componentWillUnmount: function() {
         // dis.dispatch({
-        //     action: 'ui_opacity',
-        //     sideOpacity: 1.0,
-        //     middleOpacity: 1.0,
+        //     action: 'panel_disable',
+        //     sideDisabled: false,
+        //     middleDisabled: false,
         // });
         if (this.filterTimeout) {
             clearTimeout(this.filterTimeout);
diff --git a/src/skins/vector/css/_common.scss b/src/skins/vector/css/_common.scss
index bf742cd0..a9b80928 100644
--- a/src/skins/vector/css/_common.scss
+++ b/src/skins/vector/css/_common.scss
@@ -87,6 +87,11 @@ textarea {
     transition: opacity 0.2s ease-in-out;
 }
 
+.mx_fadable.mx_fadable_faded {
+    opacity: 0.3;
+    pointer-events: none;
+}
+
 /* XXX: critical hack to GeminiScrollbar to allow them to work in FF 42 and Chrome 48.
    Stop the scrollbar view from pushing out the container's overall sizing, which causes
    flexbox to adapt to the new size and cause the view to keep growing.