diff --git a/js/src/modal.js b/js/src/modal.js
index 6b80bb2f0d..8e505eda96 100644
--- a/js/src/modal.js
+++ b/js/src/modal.js
@@ -455,8 +455,11 @@ class Modal {
   }
 
   _checkScrollbar() {
-    const rect = document.body.getBoundingClientRect()
-    this._isBodyOverflowing = rect.left + rect.right < window.innerWidth
+    const {
+      left, right
+    } = document.body.getBoundingClientRect()
+
+    this._isBodyOverflowing = Math.floor(left + right) < window.innerWidth
     this._scrollbarWidth = this._getScrollbarWidth()
   }