diff --git a/src/core/catalog.js b/src/core/catalog.js
index 54c6849ef..30ccddf16 100644
--- a/src/core/catalog.js
+++ b/src/core/catalog.js
@@ -1099,7 +1099,8 @@ class Catalog {
       visitedNodes.put(pagesRef);
     }
     const xref = this.xref,
-      pageKidsCountCache = this.pageKidsCountCache;
+      pageKidsCountCache = this.pageKidsCountCache,
+      pageIndexCache = this.pageIndexCache;
     let currentPageIndex = 0;
 
     while (nodesToVisit.length) {
@@ -1128,9 +1129,13 @@ class Catalog {
             // Cache the Page reference, since it can *greatly* improve
             // performance by reducing redundant lookups in long documents
             // where all nodes are found at *one* level of the tree.
-            if (currentNode && !pageKidsCountCache.has(currentNode)) {
+            if (!pageKidsCountCache.has(currentNode)) {
               pageKidsCountCache.put(currentNode, 1);
             }
+            // Help improve performance of the `getPageIndex` method.
+            if (!pageIndexCache.has(currentNode)) {
+              pageIndexCache.put(currentNode, currentPageIndex);
+            }
 
             if (currentPageIndex === pageIndex) {
               return [obj, currentNode];
@@ -1215,10 +1220,16 @@ class Catalog {
     if (pagesRef instanceof Ref) {
       visitedNodes.put(pagesRef);
     }
-    const map = new Map();
+    const map = new Map(),
+      pageIndexCache = this.pageIndexCache;
     let pageIndex = 0;
 
     function addPageDict(pageDict, pageRef) {
+      // Help improve performance of the `getPageIndex` method.
+      if (pageRef && !pageIndexCache.has(pageRef)) {
+        pageIndexCache.put(pageRef, pageIndex);
+      }
+
       map.set(pageIndex++, [pageDict, pageRef]);
     }
     function addPageError(error) {
diff --git a/src/core/document.js b/src/core/document.js
index 5daeeb186..06b3f3895 100644
--- a/src/core/document.js
+++ b/src/core/document.js
@@ -1285,9 +1285,14 @@ class PDFDocument {
           type = await xref.fetchAsync(type);
         }
         if (isName(type, "Page") || (!obj.has("Type") && !obj.has("Kids"))) {
-          if (ref && !catalog.pageKidsCountCache.has(ref)) {
+          if (!catalog.pageKidsCountCache.has(ref)) {
             catalog.pageKidsCountCache.put(ref, 1); // Cache the Page reference.
           }
+          // Help improve performance of the `Catalog.getPageIndex` method.
+          if (!catalog.pageIndexCache.has(ref)) {
+            catalog.pageIndexCache.put(ref, 0);
+          }
+
           return [obj, ref];
         }
       }