diff --git a/app/stylesheets/bundles/speed_grader.scss b/app/stylesheets/bundles/speed_grader.scss
index 3f1f5e6c64a..bd6717c7f1c 100644
--- a/app/stylesheets/bundles/speed_grader.scss
+++ b/app/stylesheets/bundles/speed_grader.scss
@@ -231,14 +231,17 @@ $icon-size: 1.4rem;
 
 .full_width {
   #left_side {
-    width: 100%;
+    width: calc(100% + 1px); // i.e., 100% + 8px (margin-left) - 7px (right_side width)
+    overflow-x: hidden;
     margin-#{direction(left)}: -8px;
     #left_side_inner {
       margin-#{direction(left)}: 8px;
+      width: calc(100% - 7px);
     }
   }
   #right_side {
     width: 7px;
+    overflow: hidden;
   }
   #rightside_inner {
     display: none;
@@ -247,7 +250,7 @@ $icon-size: 1.4rem;
 
 .full_height {
   height: 100%;
-  overflow-x: scroll;
+  overflow-x: auto;
 }
 
 .media_comments_visible {
@@ -343,6 +346,7 @@ $icon-size: 1.4rem;
   position: absolute;
   top: 0;
   bottom: 0;
+  overflow-y: hidden;
   #{direction(left)}: 0;
   #{direction(right)}: 25%;
   #submissions_container, #left_side_inner, iframe, #doc_preview_holder, #iframe_holder, #resize_overlay {
diff --git a/public/javascripts/jquery.doc_previews.js b/public/javascripts/jquery.doc_previews.js
index 96ebc788920..91a00bd0224 100644
--- a/public/javascripts/jquery.doc_previews.js
+++ b/public/javascripts/jquery.doc_previews.js
@@ -103,14 +103,13 @@ import './jquery.loadingImg'
         });
       }
       else if (opts.canvadoc_session_url) {
-        const canvadocWrapper = $('<div style="overflow: auto; resize: vertical;\
-        border: 1px solid transparent; height: 100%;"/>')
+        const canvadocWrapper = $('<div style="overflow: auto; border: 1px solid transparent; height: 100%;"/>')
         canvadocWrapper.appendTo($this)
         var iframe = $('<iframe/>', {
           src: opts.canvadoc_session_url,
           width: opts.width,
           allowfullscreen: '1',
-          css: {border: 0, overflow: 'auto', height: '99%', 'min-height': '800px'},
+          css: {border: 0, overflow: 'auto', height: '99%'},
           id: opts.id
         });
         iframe.appendTo(canvadocWrapper)