diff --git a/src/public/app/widgets/mobile_widgets/sidebar_container.js b/src/public/app/widgets/mobile_widgets/sidebar_container.js
index 66b9db072..3c1e5d547 100644
--- a/src/public/app/widgets/mobile_widgets/sidebar_container.js
+++ b/src/public/app/widgets/mobile_widgets/sidebar_container.js
@@ -60,7 +60,7 @@ export default class SidebarContainer extends FlexContainer {
                 this.sidebarEl.style.transition = "none";
                 this.backdropEl.style.transition = "none";
 
-                this.backdropEl.style.opacity = Math.max(0, 1 + (this.translatePercentage / 100));
+                this.backdropEl.style.opacity = (this.currentTranslate === -100 ? 0 : 1);
                 this.backdropEl.classList.add("show");
 
                 this.dragState = DRAG_STATE_DRAGGING;