diff --git a/src/components/AddSignals.js b/src/components/AddSignals.js
index dd8dac9..1705460 100644
--- a/src/components/AddSignals.js
+++ b/src/components/AddSignals.js
@@ -259,6 +259,7 @@ export default class AddSignals extends Component {
                 // see onBitDoubleClick
                 this.createSignalIfNotExtendingOne(dragStartBit, dragEndBit);
             }
+            this.propagateUpSignalChange();
             this.resetDragState();
         }
     }
diff --git a/src/components/CanGraph.js b/src/components/CanGraph.js
index 6b4b2be..b1a59c7 100644
--- a/src/components/CanGraph.js
+++ b/src/components/CanGraph.js
@@ -58,8 +58,10 @@ export default class CanGraph extends Component {
       }
     }
 
-    return nextProps.data.length != this.props.data.length
-            || !(nextProps.signalSpec.equals(this.props.signalSpec));
+    const dataChanged = nextProps.data.length != this.props.data.length
+                        || nextProps.data[0].y != nextProps.data[0].y
+                        || !(nextProps.signalSpec.equals(this.props.signalSpec));
+    return dataChanged;
   }
 
   onNewView(view) {