diff --git a/NEWS b/NEWS
index 19dbea1300b..d468ec1b74a 100644
--- a/NEWS
+++ b/NEWS
@@ -9,6 +9,8 @@ PHP                                                                        NEWS
     property). (ilutov)
   . Fixed bug GH-19044 (Protected properties are not scoped according to their
     prototype). (Bob)
+  . Fixed bug GH-18581 (Coerce numeric string keys from iterators when argument
+    unpacking). (ilutov)
 
 - Hash:
   . Fix crash on clone failure. (nielsdos)
diff --git a/Zend/tests/gh18581.phpt b/Zend/tests/gh18581.phpt
new file mode 100644
index 00000000000..cc5c0fff02e
--- /dev/null
+++ b/Zend/tests/gh18581.phpt
@@ -0,0 +1,32 @@
+--TEST--
+GH-18581: Coerce numeric string keys from iterators when argument unpacking
+--FILE--
+<?php
+
+function g() {
+    yield '100' => 'first';
+    yield '101' => 'second';
+    yield '102' => 'third';
+    yield 'named' => 'fourth';
+}
+
+function test($x = null, $y = null, ...$z) {
+    var_dump($x, $y, $z);
+    var_dump($z[0]);
+    var_dump($z['named']);
+}
+
+test(...g());
+
+?>
+--EXPECT--
+string(5) "first"
+string(6) "second"
+array(2) {
+  [0]=>
+  string(5) "third"
+  ["named"]=>
+  string(6) "fourth"
+}
+string(5) "third"
+string(6) "fourth"
diff --git a/Zend/zend_vm_def.h b/Zend/zend_vm_def.h
index 01bdcf0ad6a..d80496f3022 100644
--- a/Zend/zend_vm_def.h
+++ b/Zend/zend_vm_def.h
@@ -5329,6 +5329,11 @@ ZEND_VM_C_LABEL(send_again):
 						}
 
 						name = Z_STR_P(&key);
+
+						zend_ulong tmp;
+						if (ZEND_HANDLE_NUMERIC(name, tmp)) {
+							name = NULL;
+						}
 					}
 				}
 
diff --git a/Zend/zend_vm_execute.h b/Zend/zend_vm_execute.h
index 96bdc01746a..a1c9831f8ce 100644
--- a/Zend/zend_vm_execute.h
+++ b/Zend/zend_vm_execute.h
@@ -2419,6 +2419,11 @@ send_again:
 						}
 
 						name = Z_STR_P(&key);
+
+						zend_ulong tmp;
+						if (ZEND_HANDLE_NUMERIC(name, tmp)) {
+							name = NULL;
+						}
 					}
 				}