diff --git a/app/containers/App.js b/app/containers/App.js
index de8788b72..17cc07ece 100644
--- a/app/containers/App.js
+++ b/app/containers/App.js
@@ -10,6 +10,7 @@ import RequestPane from '../components/RequestPane'
 import ResponsePane from '../components/ResponsePane'
 import Sidebar from '../components/Sidebar'
 import {PREVIEW_MODE_FRIENDLY} from '../lib/previewModes'
+import {MAX_PANE_WIDTH, MIN_PANE_WIDTH, MAX_SIDEBAR_REMS, MIN_SIDEBAR_REMS} from '../lib/constants'
 
 import * as GlobalActions from '../redux/modules/global'
 import * as RequestGroupActions from '../redux/modules/requestGroups'
@@ -82,13 +83,14 @@ class App extends Component {
         const pixelOffset = e.clientX - requestPane.offsetLeft;
         let paneWidth = pixelOffset / (requestPaneWidth + responsePaneWidth);
 
-        paneWidth = Math.min(Math.max(paneWidth, 0.01), 0.99);
+        paneWidth = Math.min(Math.max(paneWidth, MIN_PANE_WIDTH), MAX_PANE_WIDTH);
 
         this.setState({paneWidth});
       } else if (this.state.draggingSidebar) {
         const currentPixelWidth = ReactDOM.findDOMNode(this.refs.sidebar).offsetWidth;
         const ratio = e.clientX / currentPixelWidth;
-        const sidebarWidth = Math.max(Math.min(this.state.sidebarWidth * ratio, 25), 13);
+        const width = this.state.sidebarWidth * ratio;
+        const sidebarWidth = Math.max(Math.min(width, MAX_SIDEBAR_REMS), MIN_SIDEBAR_REMS);
         this.setState({sidebarWidth})
       }
     })
diff --git a/app/lib/constants.js b/app/lib/constants.js
index 8252022d4..6a7728743 100644
--- a/app/lib/constants.js
+++ b/app/lib/constants.js
@@ -2,6 +2,12 @@
 export const LOCALSTORAGE_KEY = 'insomnia.state';
 export const DB_PERSIST_INTERVAL = 1000;
 
+// UI Stuff
+export const MAX_SIDEBAR_REMS = 35;
+export const MIN_SIDEBAR_REMS = 13;
+export const MAX_PANE_WIDTH = 0.99;
+export const MIN_PANE_WIDTH = 0.01;
+
 // HTTP Methods
 export const METHOD_GET = 'GET';
 export const METHOD_PUT = 'PUT';
diff --git a/package.json b/package.json
index b333b47fc..a056b0ff6 100644
--- a/package.json
+++ b/package.json
@@ -14,10 +14,10 @@
     "json-lint": "^0.1.0",
     "jsonschema": "^1.1.0",
     "nunjucks": "^1.3.4",
-    "react": "^0.14.7",
-    "react-dom": "^0.14.7",
+    "react": "^15.1.0",
+    "react-dom": "^15.1.0",
     "react-redux": "^4.4.1",
-    "react-tabs": "^0.5.3",
+    "react-tabs": "^0.5.4",
     "redux": "^3.3.1",
     "redux-logger": "^2.6.1",
     "redux-shortcuts": "0.0.1",
@@ -43,7 +43,7 @@
     "jest-cli": "^0.9.2",
     "json-loader": "^0.5.4",
     "node-sass": "^3.4.2",
-    "react-addons-test-utils": "^0.14.7",
+    "react-addons-test-utils": "^15.1.0",
     "react-hot-loader": "^1.3.0",
     "redux-mock-store": "^1.0.2",
     "sass-loader": "^3.2.0",