diff --git a/NEWS b/NEWS
index b9753c06aa14b..147d6ce70f504 100644
--- a/NEWS
+++ b/NEWS
@@ -21,6 +21,9 @@ PHP                                                                        NEWS
   . /dev/poll events.mechanism for Solaris/Illumos setting had been retired.
     (David Carlier)
 
+- GMP:
+  . The GMP class is now final and cannot be extended anymore.
+
 - Intl:
   . Added SpoofChecker::setAllowedChars to set unicode chars ranges.
     (David Carlier)
diff --git a/UPGRADING b/UPGRADING
index 4974182f4d4a7..0fe03244ab187 100644
--- a/UPGRADING
+++ b/UPGRADING
@@ -48,6 +48,10 @@ PHP 8.4 UPGRADE NOTES
     object. This is no longer possible, and cloning a DOMXPath object now throws
     an error.
 
+- GMP:
+  . The GMP class is now final and cannot be extended anymore.
+    RFC: https://wiki.php.net/rfc/gmp-final
+
 - Intl:
   . resourcebundle_get(), ResourceBundle::get(), and accessing offsets on a
     ResourceBundle object now throw:
diff --git a/ext/gmp/gmp.stub.php b/ext/gmp/gmp.stub.php
index ff5b5afb4055b..75812c62c5ca3 100644
--- a/ext/gmp/gmp.stub.php
+++ b/ext/gmp/gmp.stub.php
@@ -57,7 +57,7 @@
  */
 const GMP_NATIVE_ENDIAN = UNKNOWN;
 
-class GMP
+final class GMP
 {
     public function __construct(int|string $num = 0, int $base = 0) {}
 
diff --git a/ext/gmp/gmp_arginfo.h b/ext/gmp/gmp_arginfo.h
index 8126fa6686731..43d6944036888 100644
--- a/ext/gmp/gmp_arginfo.h
+++ b/ext/gmp/gmp_arginfo.h
@@ -1,5 +1,5 @@
 /* This is a generated file, edit the .stub.php file instead.
- * Stub hash: d52f82c7084a8122fe07c91eb6d4ab6030daa27d */
+ * Stub hash: 3aabd5a5d2db0df15b249a425465ae718c13ab6b */
 
 ZEND_BEGIN_ARG_WITH_RETURN_OBJ_INFO_EX(arginfo_gmp_init, 0, 1, GMP, 0)
 	ZEND_ARG_TYPE_MASK(0, num, MAY_BE_LONG|MAY_BE_STRING, NULL)
@@ -334,6 +334,7 @@ static zend_class_entry *register_class_GMP(void)
 
 	INIT_CLASS_ENTRY(ce, "GMP", class_GMP_methods);
 	class_entry = zend_register_internal_class_ex(&ce, NULL);
+	class_entry->ce_flags |= ZEND_ACC_FINAL;
 
 	return class_entry;
 }
diff --git a/ext/gmp/tests/final.phpt b/ext/gmp/tests/final.phpt
new file mode 100644
index 0000000000000..1bc485ac6e168
--- /dev/null
+++ b/ext/gmp/tests/final.phpt
@@ -0,0 +1,12 @@
+--TEST--
+Cannot extend GMP class
+--EXTENSIONS--
+gmp
+--FILE--
+<?php
+
+class T extends GMP {}
+
+?>
+--EXPECTF--
+Fatal error: Class T cannot extend final class GMP in %s on line %d