diff --git a/UPGRADING b/UPGRADING
index 0fe03244ab18..1f4604cbfd6c 100644
--- a/UPGRADING
+++ b/UPGRADING
@@ -580,8 +580,9 @@ PHP 8.4 UPGRADE NOTES
     decimal number and round it to 0.29. However, "pre-rounding" incorrectly rounds
     certain numbers, so this fix removes "pre-rounding" and changes the way numbers
     are compared, so that the values are correctly rounded as decimal numbers.
-  . The maximum precision that can be handled by round() has been extended by
-    one digit.
+  . The maximum precision that can be handled by round() has been extended by one
+    digit. For example, `round(4503599627370495.5)` returned in `4503599627370495.5`,
+    but now returns `4503599627370496`.
   . The default value of the 'cost' option for PASSWORD_BCRYPT for password_hash()
     has been increased from '10' to '12'.
 
diff --git a/ext/standard/tests/math/round_gh12143_expand-rounding-target.phpt b/ext/standard/tests/math/round_gh12143_expand_rounding_target.phpt
similarity index 100%
rename from ext/standard/tests/math/round_gh12143_expand-rounding-target.phpt
rename to ext/standard/tests/math/round_gh12143_expand_rounding_target.phpt