diff --git a/stubs/iterable.stub b/stubs/iterable.stub
index 2e10bf3889..5cefe2f196 100644
--- a/stubs/iterable.stub
+++ b/stubs/iterable.stub
@@ -403,6 +403,11 @@ class CachingIterator extends IteratorIterator implements OuterIterator, ArrayAc
      * @return TKey
      */
     public function key() {}
+
+    /**
+     * @return array<array-key, TValue>
+     */
+    public function getCache() {}
 }
 
 /**
diff --git a/tests/PHPStan/Analyser/NodeScopeResolverTest.php b/tests/PHPStan/Analyser/NodeScopeResolverTest.php
index 122089b4d4..889acc4b7b 100644
--- a/tests/PHPStan/Analyser/NodeScopeResolverTest.php
+++ b/tests/PHPStan/Analyser/NodeScopeResolverTest.php
@@ -927,6 +927,7 @@ public function dataFileAsserts(): iterable
 		yield from $this->gatherAssertTypes(__DIR__ . '/data/bug-7580.php');
 		yield from $this->gatherAssertTypes(__DIR__ . '/data/this-subtractable.php');
 		yield from $this->gatherAssertTypes(__DIR__ . '/data/match-expression-inference.php');
+		yield from $this->gatherAssertTypes(__DIR__ . '/data/bug-1519.php');
 	}
 
 	/**
diff --git a/tests/PHPStan/Analyser/data/bug-1519.php b/tests/PHPStan/Analyser/data/bug-1519.php
new file mode 100644
index 0000000000..7d01391c63
--- /dev/null
+++ b/tests/PHPStan/Analyser/data/bug-1519.php
@@ -0,0 +1,22 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App;
+
+use Generator;
+use CachingIterator;
+use function PHPStan\Testing\assertType;
+
+$generator =
+    /**
+     * @return Generator<bool, bool>
+     */
+    static function (): Generator {
+      yield true => true;
+      yield false => false;
+    };
+
+$iterator = new CachingIterator($generator(), CachingIterator::FULL_CACHE);
+$cache = $iterator->getCache();
+assertType('array<bool>', $cache);