diff --git a/Zend/tests/gh21504.inc b/Zend/tests/gh21504.inc
new file mode 100644
index 0000000000000..71dc5c2e61f64
--- /dev/null
+++ b/Zend/tests/gh21504.inc
@@ -0,0 +1,3 @@
+<?php
+
+'1234' |> var_dump(...);
diff --git a/Zend/tests/gh21504.phpt b/Zend/tests/gh21504.phpt
new file mode 100644
index 0000000000000..5fd9eaff91ab6
--- /dev/null
+++ b/Zend/tests/gh21504.phpt
@@ -0,0 +1,12 @@
+--TEST--
+GH-21504: Incorrect RC-handling for ZEND_EXT_STMT op1
+--FILE--
+<?php
+
+$php_escaped = getenv('TEST_PHP_EXECUTABLE_ESCAPED');
+$cmd = $php_escaped . ' -n -e ' . escapeshellarg(__DIR__ . '/gh21504.inc');
+echo shell_exec($cmd);
+
+?>
+--EXPECT--
+string(4) "1234"
diff --git a/Zend/zend_compile.c b/Zend/zend_compile.c
index 80f85f421a331..8c748fc8ccc4c 100644
--- a/Zend/zend_compile.c
+++ b/Zend/zend_compile.c
@@ -1934,6 +1934,9 @@ static void zend_do_extended_stmt(znode* result) /* {{{ */
 
 	opline->opcode = ZEND_EXT_STMT;
 	if (result) {
+		if (result->op_type == IS_CONST) {
+			Z_TRY_ADDREF(result->u.constant);
+		}
 		SET_NODE(opline->op1, result);
 	}
 }