diff --git a/app/src/actions/ConnectionManager.ts b/app/src/actions/ConnectionManager.ts
index 9325072..7c9fd95 100644
--- a/app/src/actions/ConnectionManager.ts
+++ b/app/src/actions/ConnectionManager.ts
@@ -15,7 +15,9 @@ import * as path from 'path'
 
 import { ActionTypes, Action } from '../reducers/ConnectionManager'
 
-type ConnectionDictionary = { [s: string]: ConnectionOptions }
+interface ConnectionDictionary {
+  [s: string]: ConnectionOptions
+}
 const storedConnectionsIdentifier: StorageIdentifier<ConnectionDictionary> = {
   id: 'ConnectionManager_connections',
 }
diff --git a/app/src/components/Sidebar/CodeDiff/ChartPreview.tsx b/app/src/components/Sidebar/CodeDiff/ChartPreview.tsx
index f0f1243..bce0371 100644
--- a/app/src/components/Sidebar/CodeDiff/ChartPreview.tsx
+++ b/app/src/components/Sidebar/CodeDiff/ChartPreview.tsx
@@ -38,7 +38,7 @@ function ChartPreview(props: Props) {
 
   const hasEnoughDataToDisplayDiagrams = props.treeNode.messageHistory.count() > 1
 
-  let preview = hasEnoughDataToDisplayDiagrams ? (
+  const addChartToPanelButton = hasEnoughDataToDisplayDiagrams ? (
     <Tooltip title="Click to add to chart panel">
       <ShowChart
         ref={chartIconRef}
@@ -56,7 +56,7 @@ function ChartPreview(props: Props) {
 
   return (
     <span>
-      {preview}
+      {addChartToPanelButton}
       <Popper open={open} anchorEl={chartIconRef.current} placement="left-end">
         <Fade in={open} timeout={300}>
           <Paper style={{ width: '300px' }}>
diff --git a/app/src/components/Sidebar/PlotHistory.tsx b/app/src/components/Sidebar/PlotHistory.tsx
index 3428f33..4889287 100644
--- a/app/src/components/Sidebar/PlotHistory.tsx
+++ b/app/src/components/Sidebar/PlotHistory.tsx
@@ -1,4 +1,3 @@
-import * as q from '../../../../backend/src/Model'
 import * as React from 'react'
 import DateFormatter from '../helper/DateFormatter'
 import { default as ReactResizeDetector } from 'react-resize-detector'