diff --git a/tools/code_samples/code_samples_usage_diff2html.php b/tools/code_samples/code_samples_usage_diff2html.php
index 965cd3f6ae..f15f6fe28c 100644
--- a/tools/code_samples/code_samples_usage_diff2html.php
+++ b/tools/code_samples/code_samples_usage_diff2html.php
@@ -33,7 +33,7 @@
         continue;
     }
     $statusChar = strlen($diffLine) ? $diffLine[0] : '';
-    $realLine = $str = substr($diffLine, 1);
+    $realLine = str_replace(['<', '>'], ['&lt;', '&gt;'], substr($diffLine, 1));
     if ($previousStatusChar !== $statusChar) {
         switch ("$previousStatusChar$statusChar") {
             case ' +':