diff --git a/shared/js/ui/elements/Slider.ts b/shared/js/ui/elements/Slider.ts
index 669f2cf1..87238dd3 100644
--- a/shared/js/ui/elements/Slider.ts
+++ b/shared/js/ui/elements/Slider.ts
@@ -73,7 +73,7 @@ export function sliderfy(slider: JQuery, options?: SliderOptions) : Slider {
         const parent_offset = slider.offset();
         const min = parent_offset.left;
         const max = parent_offset.left + slider.width();
-        const current = 'touches' in event ? event.touches[event.touches.length - 1].clientX : event.pageX;
+        const current = ('touches' in event && Array.isArray(event.touches) && event.touches.length > 0) ? event.touches[event.touches.length - 1].clientX : (event as MouseEvent).pageX;
 
         const range = options.max_value - options.min_value;
         const offset = Math.round(((current - min) * (range / options.step)) / (max - min)) * options.step;