diff --git a/_sass/_base.scss b/_sass/_base.scss
index 095d68c8862e..e83d94b1e585 100644
--- a/_sass/_base.scss
+++ b/_sass/_base.scss
@@ -1058,3 +1058,12 @@ nav[data-toggle="toc"] {
     padding-top: 0.5rem;
   }
 }
+
+.medium-zoom-overlay,
+.medium-zoom-image--opened {
+  z-index: 999;
+}
+
+#toc-sidebar {
+  z-index: 1;
+}