diff --git a/assets/js/just-the-docs.js b/assets/js/just-the-docs.js
index 87fa9b5..0835d66 100644
--- a/assets/js/just-the-docs.js
+++ b/assets/js/just-the-docs.js
@@ -76,7 +76,9 @@ function initNav() {
 // The page-specific stylesheet is assumed to have index 1 in the list of stylesheets.
 
 function disableHeadStyleSheet() {
-  document.styleSheets[1].disabled = true;
+  if (document.styleSheets[1]) {
+    document.styleSheets[1].disabled = true;
+  }
 }
 
 {%- if site.search_enabled != false %}