diff --git a/ChartsSpace/ViewPort.js b/ChartsSpace/ViewPort.js
index 7a66442cf..01b7d5627 100644
--- a/ChartsSpace/ViewPort.js
+++ b/ChartsSpace/ViewPort.js
@@ -204,7 +204,8 @@ function newViewport () {
     let newEvent = {
       newLevel: thisObject.zoomTargetLevel,
       newPosition: position,
-      type: undefined
+      type: undefined,
+      shiftKey: event.shiftKey
     }
 
     if (amount > 0) {
diff --git a/Scales/TimeFrameScale.js b/Scales/TimeFrameScale.js
index e6e49e99b..7477ccb7b 100644
--- a/Scales/TimeFrameScale.js
+++ b/Scales/TimeFrameScale.js
@@ -179,6 +179,7 @@ function newTimeFrameScale () {
 
   function onViewportZoomChanged (event) {
     if (event !== undefined) { // it is undefined when the level is just being animated.
+      if (event.shiftKey === false) { return } // with no shft key pressed, no automatic change in scale
       let currentTimeFrame = thisObject.timeFrame
       let timeFrame = recalculatePeriod(event.newLevel)
       if (timeFrame !== currentTimeFrame) {