diff --git a/app/src/components/Sidebar/MessageHistory.tsx b/app/src/components/Sidebar/MessageHistory.tsx
index a03e114..8e2ef6f 100644
--- a/app/src/components/Sidebar/MessageHistory.tsx
+++ b/app/src/components/Sidebar/MessageHistory.tsx
@@ -55,7 +55,7 @@ class MessageHistory extends React.Component<Props, State> {
       value: message.value,
     }))
 
-    const numericMessages = history.filter(message => !isNaN(message.value))
+    const numericMessages = history.filter(message => !isNaN(parseFloat(message.value)))
     const showPlot = numericMessages.length >= 2
 
     return (
@@ -65,7 +65,7 @@ class MessageHistory extends React.Component<Props, State> {
           contentTypeIndicator={showPlot ? <BarChart /> : null}
           onClick={this.displayMessage}
         >
-          {showPlot ? this.renderPlot(history) : null}
+          {showPlot ? this.renderPlot(numericMessages) : null}
         </History>
       </div>
     )
diff --git a/app/src/components/Sidebar/PlotHistory.tsx b/app/src/components/Sidebar/PlotHistory.tsx
index 4ba2590..2d8898e 100644
--- a/app/src/components/Sidebar/PlotHistory.tsx
+++ b/app/src/components/Sidebar/PlotHistory.tsx
@@ -29,8 +29,8 @@ class PlotHistory extends React.Component<Props, Stats> {
   public render() {
     const data = this.props.messages.map((message) => {
       return {
-        x: message.received,
-        y: message.value,
+        x: message.received.getTime(),
+        y: parseFloat(message.value),
       }
     })