diff --git a/tests/Rule/data/EnforceIteratorToArrayPreserveKeysRule/code.php b/tests/Rule/data/EnforceIteratorToArrayPreserveKeysRule/code.php
index 54745e9..16f83d4 100644
--- a/tests/Rule/data/EnforceIteratorToArrayPreserveKeysRule/code.php
+++ b/tests/Rule/data/EnforceIteratorToArrayPreserveKeysRule/code.php
@@ -2,6 +2,13 @@
 
 namespace EnforceIteratorToArrayPreserveKeysRule;
 
+/**
+ * Isolate the generator, so that PHPStan is not aware of the keys.
+ */
+function passThru(\Generator $iterable): \Generator {
+    yield from $iterable;
+}
+
 $objectAsKey = function () {
     yield new \stdClass => 1;
 };
@@ -17,15 +24,15 @@
 };
 
 
-iterator_to_array($objectAsKey()); // error: Calling iterator_to_array without 2nd parameter $preserve_keys. Default value true might cause failures or data loss.
-iterator_to_array($dataLoss()); // error: Calling iterator_to_array without 2nd parameter $preserve_keys. Default value true might cause failures or data loss.
-iterator_to_array($noKeys()); // error: Calling iterator_to_array without 2nd parameter $preserve_keys. Default value true might cause failures or data loss.
+iterator_to_array(passThru($objectAsKey())); // error: Calling iterator_to_array without 2nd parameter $preserve_keys. Default value true might cause failures or data loss.
+iterator_to_array(passThru($dataLoss())); // error: Calling iterator_to_array without 2nd parameter $preserve_keys. Default value true might cause failures or data loss.
+iterator_to_array(passThru($noKeys())); // error: Calling iterator_to_array without 2nd parameter $preserve_keys. Default value true might cause failures or data loss.
 
-iterator_to_array($objectAsKey(), false);
-iterator_to_array($dataLoss(), false);
-iterator_to_array($noKeys(), true);
-iterator_to_array(... [$noKeys(), true]);
+iterator_to_array(passThru($objectAsKey()), false);
+iterator_to_array(passThru($dataLoss()), false);
+iterator_to_array(passThru($noKeys()), true);
+iterator_to_array(... [passThru($noKeys()), true]);
 iterator_to_array(
     preserve_keys: true,
-    iterator: $noKeys()
+    iterator: passThru($noKeys())
 );