core/modules/big_pipe/src/Render/BigPipe.php | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/core/modules/big_pipe/src/Render/BigPipe.php b/core/modules/big_pipe/src/Render/BigPipe.php
index 16c862a..9145208 100644
--- a/core/modules/big_pipe/src/Render/BigPipe.php
+++ b/core/modules/big_pipe/src/Render/BigPipe.php
@@ -129,7 +129,9 @@ public function sendContent($content, array $attachments) {
     // Find the closing </body> tag and get the strings before and after. But be
     // careful to use the latest occurrence of the string "</body>", to ensure
     // that strings in inline JavaScript or CDATA sections aren't used instead.
-    list($pre_body, $post_body) = array_reverse(array_map('strrev', explode(strrev('</body>'), strrev($content), 2)));
+    $parts = explode('</body>', $content);
+    $post_body = array_pop($parts);
+    $pre_body = implode('', $parts);
 
     $this->sendPreBody($pre_body, $nojs_placeholders, $cumulative_assets);
     $this->sendPlaceholders($placeholders, $this->getPlaceholderOrder($pre_body), $cumulative_assets);