diff --git a/core/modules/system/src/Tests/Pager/PagerTest.php b/core/modules/system/src/Tests/Pager/PagerTest.php
index d25dd9a..b20e974 100644
--- a/core/modules/system/src/Tests/Pager/PagerTest.php
+++ b/core/modules/system/src/Tests/Pager/PagerTest.php
@@ -108,6 +108,10 @@ protected function assertPagerItems($current_page) {
     // Make current page 1-based.
     $current_page++;
 
+    // We remove elements from the $elements array in the following code, so
+    // we store the total number of pages for verifying the "last" link.
+    $total_pages = count($elements);
+
     // Extract first/previous and next/last items.
     // first/previous only exist, if the current page is not the first.
     if ($current_page > 1) {
@@ -118,7 +122,6 @@ protected function assertPagerItems($current_page) {
     if ($current_page != count($elements)) {
       $last = array_pop($elements);
       $next = array_pop($elements);
-      $total_pages = count($elements);
     }
 
     // Verify items and links to pages.