diff --git a/src/plugins/vis_type_timeseries/public/application/components/vis_types/timeseries/vis.js b/src/plugins/vis_type_timeseries/public/application/components/vis_types/timeseries/vis.js
index af923920f6b45..f936710bf2b81 100644
--- a/src/plugins/vis_type_timeseries/public/application/components/vis_types/timeseries/vis.js
+++ b/src/plugins/vis_type_timeseries/public/application/components/vis_types/timeseries/vis.js
@@ -201,8 +201,6 @@ export class TimeseriesVisualization extends Component {
           seriesDataRow.useDefaultGroupDomain = !isCustomDomain;
         });
 
-      const tickFormatter = allSeriesHaveSameFormatters ? seriesGroupTickFormatter : (val) => val;
-
       if (isCustomDomain) {
         TimeseriesVisualization.addYAxis(yAxis, {
           domain,
@@ -217,7 +215,7 @@ export class TimeseriesVisualization extends Component {
         });
       } else if (!mainDomainAdded) {
         TimeseriesVisualization.addYAxis(yAxis, {
-          tickFormatter: series.length === 1 ? undefined : tickFormatter,
+          tickFormatter: allSeriesHaveSameFormatters ? seriesGroupTickFormatter : (val) => val,
           id: yAxisIdGenerator('main'),
           groupId: mainAxisGroupId,
           position: model.axis_position,