diff --git a/highcharts/highcharts-tests.ts b/highcharts/highcharts-tests.ts
index f163f2a305..456209a33d 100644
--- a/highcharts/highcharts-tests.ts
+++ b/highcharts/highcharts-tests.ts
@@ -135,3 +135,11 @@ var highChartSettings: HighchartsOptions = {
 var container = $("#container").highcharts(highChartSettings, (chart) => {
     chart.series[0].setVisible(true, true);
 });
+
+
+var singleYAxisOptions: HighchartsOptions = {
+    yAxis: {}
+};
+var multipleYAxisOptions: HighchartsOptions = {
+    yAxis: [{},{}]
+};
\ No newline at end of file
diff --git a/highcharts/highcharts.d.ts b/highcharts/highcharts.d.ts
index 483e37fca3..2341f87693 100644
--- a/highcharts/highcharts.d.ts
+++ b/highcharts/highcharts.d.ts
@@ -1169,7 +1169,7 @@ interface HighchartsOptions {
     title?: HighchartsTitleOptions;
     tooltip?: HighchartsTooltipOptions;
     xAxis?: HighchartsAxisOptions;
-    yAxis?: HighchartsAxisOptions;
+    yAxis?: HighchartsAxisOptions|HighchartsAxisOptions[];
 }
 
 interface HighchartsGlobalOptions extends HighchartsOptions {