diff --git a/__tests__/integration/mirador/index.html b/__tests__/integration/mirador/index.html
index 46a2a53a1f9d4091e7770b40dd8981f01aa86fc6..5c097b29396425ee4ea3f7b69922b2546a291d6a 100644
--- a/__tests__/integration/mirador/index.html
+++ b/__tests__/integration/mirador/index.html
@@ -7,7 +7,7 @@
     <title>Mirador</title>
   </head>
   <body>
-    <div id="mirador"></div>
+    <div id="mirador" style="position: absolute; top: 0; bottom: 0; left: 0; right: 0;"></div>
     <script>document.write("<script type='text/javascript' src='../../../dist/mirador.min.js?v=" + Date.now() + "'><\/script>");</script>
     <script type="text/javascript">
      var miradorInstance = Mirador.viewer({
diff --git a/__tests__/integration/mirador/plugins.html b/__tests__/integration/mirador/plugins.html
index df5ddbd9e3efdc624bc4ef0b3d171260eb14e788..3310af53b64fd24c985824bdd26fede98097c0c0 100644
--- a/__tests__/integration/mirador/plugins.html
+++ b/__tests__/integration/mirador/plugins.html
@@ -7,7 +7,7 @@
     <title>Mirador</title>
   </head>
   <body>
-    <div id="mirador"></div>
+    <div id="mirador" style="position: absolute; top: 0; bottom: 0; left: 0; right: 0;"></div>
     <script src="../../../node_modules/react/umd/react.development.js"></script>
     <!-- Request from CDN if unavailable locally -->
     <script type="text/javascript">
diff --git a/src/styles/index.scss b/src/styles/index.scss
index c7932e0ad740fb41574ea3cab8fa01bfc4cff5ba..cd70bf40fbe52aaf9a456390c4b401f20eb323b2 100644
--- a/src/styles/index.scss
+++ b/src/styles/index.scss
@@ -1,6 +1,12 @@
 @import 'variables';
 
 .mirador {
+  &-app {
+    height: 100%;
+    position: relative;
+    width: 100%;
+  }
+
   &-workspace {
     bottom: 0;
     box-sizing: border-box;