diff --git a/x-pack/plugins/ml/public/application/timeseriesexplorer/components/timeseries_chart/timeseries_chart.js b/x-pack/plugins/ml/public/application/timeseriesexplorer/components/timeseries_chart/timeseries_chart.js
index 32fa27b70989e..768de330cce1d 100644
--- a/x-pack/plugins/ml/public/application/timeseriesexplorer/components/timeseries_chart/timeseries_chart.js
+++ b/x-pack/plugins/ml/public/application/timeseriesexplorer/components/timeseries_chart/timeseries_chart.js
@@ -689,7 +689,7 @@ class TimeseriesChartIntl extends Component {
         const levels = getAnnotationLevels(focusAnnotationData);
         const maxLevel = d3.max(Object.keys(levels).map((key) => levels[key]));
         // TODO needs revisiting to be a more robust normalization
-        yMax = yMax * (1 + (maxLevel + 1) / 5);
+        yMax += Math.abs(yMax - yMin) * ((maxLevel + 1) / 5);
       }
       this.focusYScale.domain([yMin, yMax]);
     } else {