diff --git a/reviewboard/static/rb/css/mixins/upload-diff.less b/reviewboard/static/rb/css/mixins/upload-diff.less
index b5a09b893bc4a8b953201af6d31b797c8430bc9d..32031859e2896dab079cef6ecb4689531fa9e6cd 100644
--- a/reviewboard/static/rb/css/mixins/upload-diff.less
+++ b/reviewboard/static/rb/css/mixins/upload-diff.less
@@ -29,6 +29,13 @@
     text-align: center;
     vertical-align: middle;
 
+    > form {
+      display: flex;
+      align-items: center;
+      justify-content: center;
+      gap: 1ch;
+    }
+
     .startover {
       position: absolute;
       bottom: 0;
diff --git a/reviewboard/static/rb/js/views/updateDiffView.es6.js b/reviewboard/static/rb/js/views/updateDiffView.es6.js
index 125b3205aa17413a078c48f91971fafc69076712..75ceeeff3971cd4e4b5addfd572b72ed48c27fb0 100644
--- a/reviewboard/static/rb/js/views/updateDiffView.es6.js
+++ b/reviewboard/static/rb/js/views/updateDiffView.es6.js
@@ -21,15 +21,15 @@ RB.UpdateDiffView = RB.UploadDiffView.extend({
          <form id="basedir-form">
           <%- baseDir %>
           <input id="basedir-input">
-          <input type="submit" value="<%- ok %>">
+          <button class="ink-c-button" type="submit">"<%- ok %>"</button>
          </form>
          <a href="#" class="startover"><%- startOver %></a>
         </div>
         <div class="input" id="processing-diff">
-         <div class="spinner"><span class="djblets-o-spinner"></div>
+         <div class="spinner"><span class="ink-c-spinner"></span></div>
         </div>
         <div class="input" id="uploading-diffs">
-         <div class="spinner"><span class="djblets-o-spinner"></div>
+         <div class="spinner"><span class="ink-c-spinner"></span></div>
         </div>
         <div class="input" id="error-indicator">
          <div id="error-contents"></div>
@@ -49,11 +49,14 @@ RB.UpdateDiffView = RB.UploadDiffView.extend({
 
         this.$el
             .modalBox({
-                title: gettext('Update Diff'),
                 buttons: [
-                    $('<input type="button">')
-                        .val(gettext('Cancel')),
+                    Ink.paintComponent(
+                        'Ink.Button',
+                        {},
+                        _`Cancel`
+                    ),
                 ],
+                title: _`Update Diff`,
             })
             .on('close', () => this.$el.modalBox('destroy'));
 
diff --git a/reviewboard/static/rb/js/views/uploadDiffView.es6.js b/reviewboard/static/rb/js/views/uploadDiffView.es6.js
index 4a6c2c7185fa2fb22ebc7b46e3c7bb75ea9a6924..ba823102e5a8561ea45ef31c40e19e051eaf292c 100644
--- a/reviewboard/static/rb/js/views/uploadDiffView.es6.js
+++ b/reviewboard/static/rb/js/views/uploadDiffView.es6.js
@@ -37,11 +37,27 @@ RB.UploadDiffView = Backbone.View.extend({
         let selectParentDiffText;
 
         if (this._canDragDrop()) {
-            selectDiffText = gettext('<input type="button" id="select-diff-file" value="Select"> or drag and drop a diff file to begin');
-            selectParentDiffText = gettext('<input type="button" id="select-parent-diff-file" value="Select"> or drag and drop a parent diff file if you have one');
+            selectDiffText = _`
+                <button class="ink-c-button" type="button"
+                id="select-diff-file">Select</button>
+                or drag and drop a diff file to begin
+            `;
+            selectParentDiffText = _`
+                <button class="ink-c-button" type="button"
+                id="select-parent-diff-file">Select</button>
+                or drag and drop a parent diff file if you have one
+            `;
         } else {
-            selectDiffText = gettext('<input type="button" id="select-diff-file" value="Select"> a file to begin');
-            selectParentDiffText = gettext('<input type="button" id="select-parent-diff-file" value="Select"> a parent diff file if you have one');
+            selectDiffText = _`
+                <button class="ink-c-button" type="button"
+                id="select-diff-file">Select</button>
+                a file to begin
+            `;
+            selectParentDiffText = _`
+                <button class="ink-c-button" type="button"
+                id="select-parent-diff-file">Select</button>
+                a parent diff file if you have one
+            `;
         }
 
         this.$el.html(this.template({