diff --git a/UPGRADING b/UPGRADING
index 10734853303..8a4943748f4 100644
--- a/UPGRADING
+++ b/UPGRADING
@@ -370,6 +370,9 @@ PHP 8.1 UPGRADE NOTES
   . The filter.default ini setting is deprecated.
     RFC: https://wiki.php.net/rfc/deprecations_php_8_1
 
+- GD:
+  . The $num_points parameter of image(open|filled)polygon has been deprecated.
+
 - Hash:
   . The mhash(), mhash_keygen_s2k(), mhash_count(), mhash_get_block_size() and
     mhash_get_hash_name() functions are deprecated. Use the hash_*() APIs
diff --git a/ext/gd/gd.c b/ext/gd/gd.c
index f7723e166fb..6634ec8b851 100644
--- a/ext/gd/gd.c
+++ b/ext/gd/gd.c
@@ -2726,6 +2726,8 @@ static void php_imagepolygon(INTERNAL_FUNCTION_PARAMETERS, int filled)
 			RETURN_THROWS();
 		}
 		NPOINTS /= 2;
+	} else {
+		php_error_docref(NULL, E_DEPRECATED, "Using the $num_points parameter is deprecated");
 	}
 
 	im = php_gd_libgdimageptr_from_zval_p(IM);
diff --git a/ext/gd/tests/bug55005.phpt b/ext/gd/tests/bug55005.phpt
index d29dfc61084..0771fa6d617 100644
--- a/ext/gd/tests/bug55005.phpt
+++ b/ext/gd/tests/bug55005.phpt
@@ -14,6 +14,9 @@ trycatch_dump(
     fn () => imagepolygon($g, array(200,10, 200,100, 280,100), 2, $fgnd)
 );
 ?>
---EXPECT--
+--EXPECTF--
+Deprecated: imagefilledpolygon(): Using the $num_points parameter is deprecated in %s on line %d
 !! [ValueError] imagefilledpolygon(): Argument #3 ($num_points_or_color) must be greater than or equal to 3
+
+Deprecated: imagepolygon(): Using the $num_points parameter is deprecated in %s on line %d
 !! [ValueError] imagepolygon(): Argument #3 ($num_points_or_color) must be greater than or equal to 3