diff --git a/shared/lib/archive-history.js b/shared/lib/archive-history.js
index 29bee7e..1f619c1 100644
--- a/shared/lib/archive-history.js
+++ b/shared/lib/archive-history.js
@@ -28,20 +28,20 @@ class ArchiveHistory extends History {
     // downstream call of `urlRouter.attach()` which we do when bootstraping
     // everything.
     if (window.history) {
-      let replacingUrl = window.location.search + url;
+      let replacingUrl = document?.location?.search + url;
       // This is a way to make sure the hash gets cleared out
       if (url === '') {
-        replacingUrl = window.location.pathname + window.location.search;
+        replacingUrl = document?.location?.pathname + document?.location?.search;
       }
       super.replaceUrlSilently(replacingUrl);
     }
   }
 
   pushUrlSilently(url) {
-    let replacingUrl = window.location.search + url;
+    let replacingUrl = document?.location?.search + url;
     // This is a way to make sure the hash gets cleared out
     if (url === '') {
-      replacingUrl = window.location.pathname + window.location.search;
+      replacingUrl = document?.location?.pathname + document?.location?.search;
     }
     super.pushUrlSilently(replacingUrl);
   }
diff --git a/shared/views/ModalView.js b/shared/views/ModalView.js
index ba133c5..585e635 100644
--- a/shared/views/ModalView.js
+++ b/shared/views/ModalView.js
@@ -81,9 +81,12 @@ class ModalView extends TemplateView {
         // The dialog has to be in the DOM before we can call `showModal`, etc.
         // Assume this view will be mounted in the parent DOM straight away.
         requestAnimationFrame(() => {
-          if (open) {
+          // Prevent doing extra work if the modal is already closed or open and already
+          // matches our intention
+          const isAlreadyOpen = !!dialog.getAttribute('open');
+          if (open && !isAlreadyOpen) {
             this.showModal();
-          } else {
+          } else if (isAlreadyOpen) {
             this.closeModal();
           }
         });
@@ -98,6 +101,10 @@ class ModalView extends TemplateView {
   }
 
   onDialogClicked(event) {
+    // Close the dialog when the backdrop is clicked. The `::backdrop` is considered
+    // part of the `dialogNode` but we have a `modalInner` element that stops clicks on
+    // the dialog content itself counting as a click on it. So the only clicks to the
+    // dialog will be on the backdrop and we can safely assume they meant to close it.
     if (event.target === this.dialogNode) {
       this.closeModal();
     }