diff --git a/internal/js/files_support.js b/internal/js/files_support.js
index 62fb546..f27bab0 100644
--- a/internal/js/files_support.js
+++ b/internal/js/files_support.js
@@ -614,9 +614,7 @@ function isLastPage(pageNumber)
 function getPageNumberForId(id) {
     const idx = entryList.indexOf(id);
     // should be impossible but jic
-    if (idx === -1) {
-        return -1; // or null, if you prefer
-    }
+    if (idx === -1) { return -1 }
     return Math.floor(idx / OPT.how_many) + 1;
 }