diff --git a/ckan/public/base/javascript/modules/data-viewer.js b/ckan/public/base/javascript/modules/data-viewer.js
index 7ee76da80f7..8415f1583e8 100644
--- a/ckan/public/base/javascript/modules/data-viewer.js
+++ b/ckan/public/base/javascript/modules/data-viewer.js
@@ -26,7 +26,7 @@ this.ckan.module('data-viewer', function (jQuery) {
     _recalibrate: function() {
       // save reference to this to use in timeout
       var that = this;
-      MIN_HEIGHT = 300;
+      MIN_HEIGHT = 400;
 
       resizeTimer = setTimeout(function() {
         var height = that.el.contents().find('body').get(0).scrollHeight;
diff --git a/ckan/public/base/less/module.less b/ckan/public/base/less/module.less
index 111d14cfbfc..b0186555d5b 100644
--- a/ckan/public/base/less/module.less
+++ b/ckan/public/base/less/module.less
@@ -174,3 +174,19 @@
 .group-listing {
   margin-left: -20px; // Same as .row
 }
+
+// PREVIEW
+
+.ckanext-datapreview {
+  position: relative;
+  overflow: auto;
+
+  & > iframe {
+    min-height: 400px;
+  }
+  & > img {
+    max-height: 500px;
+    max-width: 100%;
+    overflow: hidden;
+  }
+}
diff --git a/ckan/templates/dataviewer/pdf.html b/ckan/templates/dataviewer/pdf.html
index f41bb5a91de..f2cb4bc5cbe 100644
--- a/ckan/templates/dataviewer/pdf.html
+++ b/ckan/templates/dataviewer/pdf.html
@@ -150,8 +150,9 @@
 
 {% block scripts %}
   {{ super() }}
-  {% resource 'datapreview/pdf' %}
+
   <script>
     var pdfjs_workerSrc = "{{ h.urls_for_resource('datapreview/vendor/pdfjs/pdf.js')[0] }}";
   </script>
+  {% resource 'datapreview/pdf' %}
 {% endblock %}
diff --git a/ckan/templates/dataviewer/snippets/data_preview.html b/ckan/templates/dataviewer/snippets/data_preview.html
index ff8f03b8508..48ce3b16e1c 100644
--- a/ckan/templates/dataviewer/snippets/data_preview.html
+++ b/ckan/templates/dataviewer/snippets/data_preview.html
@@ -1,7 +1,7 @@
-<div class="module-content" class="ckanext-datapreview">
+<div class="module-content ckanext-datapreview">
   {% if embed %}
     {# images can be embedded directly #}
-    <img class="ckanext-datapreview-direct-embed" src="{{ resource_url }}"></img>
+    <img src="{{ resource_url }}"></img>
   {% else %}
     <iframe src="{{ resource_url }}" frameborder="0" width="100%" data-module="data-viewer">
       <p>{{ _('Your browser does not support iframes.') }}</p>