diff --git a/src/Reflection/ClassReflection.php b/src/Reflection/ClassReflection.php
index 48e9c7e648..8294ae89b4 100644
--- a/src/Reflection/ClassReflection.php
+++ b/src/Reflection/ClassReflection.php
@@ -826,25 +826,33 @@ private function getAncestors(): array
 				$this->getName() => $this,
 			];
 
+			$addToAncestors = static function (string $name, ClassReflection $classReflection) use (&$ancestors): void {
+				if (array_key_exists($name, $ancestors)) {
+					return;
+				}
+
+				$ancestors[$name] = $classReflection;
+			};
+
 			foreach ($this->getInterfaces() as $interface) {
-				$ancestors[$interface->getName()] = $interface;
+				$addToAncestors($interface->getName(), $interface);
 				foreach ($interface->getAncestors() as $name => $ancestor) {
-					$ancestors[$name] = $ancestor;
+					$addToAncestors($name, $ancestor);
 				}
 			}
 
 			foreach ($this->getTraits() as $trait) {
-				$ancestors[$trait->getName()] = $trait;
+				$addToAncestors($trait->getName(), $trait);
 				foreach ($trait->getAncestors() as $name => $ancestor) {
-					$ancestors[$name] = $ancestor;
+					$addToAncestors($name, $ancestor);
 				}
 			}
 
 			$parent = $this->getParentClass();
 			if ($parent !== false) {
-				$ancestors[$parent->getName()] = $parent;
+				$addToAncestors($parent->getName(), $parent);
 				foreach ($parent->getAncestors() as $name => $ancestor) {
-					$ancestors[$name] = $ancestor;
+					$addToAncestors($name, $ancestor);
 				}
 			}
 
diff --git a/tests/PHPStan/Analyser/NodeScopeResolverTest.php b/tests/PHPStan/Analyser/NodeScopeResolverTest.php
index 1e3039e44c..1999addd54 100644
--- a/tests/PHPStan/Analyser/NodeScopeResolverTest.php
+++ b/tests/PHPStan/Analyser/NodeScopeResolverTest.php
@@ -9773,6 +9773,11 @@ public function dataBug2648(): array
 		return $this->gatherAssertTypes(__DIR__ . '/data/bug-2648.php');
 	}
 
+	public function dataBug2740(): array
+	{
+		return $this->gatherAssertTypes(__DIR__ . '/data/bug-2740.php');
+	}
+
 	/**
 	 * @dataProvider dataBug2574
 	 * @dataProvider dataBug2577
@@ -9791,6 +9796,7 @@ public function dataBug2648(): array
 	 * @dataProvider dataPsalmPrefixedTagsWithUnresolvableTypes
 	 * @dataProvider dataComplexGenericsExample
 	 * @dataProvider dataBug2648
+	 * @dataProvider dataBug2740
 	 * @param ConstantStringType $expectedType
 	 * @param Type $actualType
 	 */
diff --git a/tests/PHPStan/Analyser/data/bug-2740.php b/tests/PHPStan/Analyser/data/bug-2740.php
new file mode 100644
index 0000000000..a5cdb70781
--- /dev/null
+++ b/tests/PHPStan/Analyser/data/bug-2740.php
@@ -0,0 +1,12 @@
+<?php
+
+namespace Bug2740;
+
+use function PHPStan\Analyser\assertType;
+
+function (Member $member): void
+{
+	foreach ($member as $i) {
+		assertType('Bug2740\Member', $i);
+	}
+};
diff --git a/tests/PHPStan/Rules/Methods/MissingMethodReturnTypehintRuleTest.php b/tests/PHPStan/Rules/Methods/MissingMethodReturnTypehintRuleTest.php
index 71b15c4c92..330a16455e 100644
--- a/tests/PHPStan/Rules/Methods/MissingMethodReturnTypehintRuleTest.php
+++ b/tests/PHPStan/Rules/Methods/MissingMethodReturnTypehintRuleTest.php
@@ -50,4 +50,9 @@ public function testRule(): void
 		]);
 	}
 
+	public function testIndirectInheritanceBug2740(): void
+	{
+		$this->analyse([__DIR__ . '/data/bug2740.php'], []);
+	}
+
 }
diff --git a/tests/PHPStan/Rules/Methods/data/bug2740.php b/tests/PHPStan/Rules/Methods/data/bug2740.php
new file mode 100644
index 0000000000..731a62d0ed
--- /dev/null
+++ b/tests/PHPStan/Rules/Methods/data/bug2740.php
@@ -0,0 +1,66 @@
+<?php
+
+namespace Bug2740;
+
+/**
+ * A collection that can contain members.
+ *
+ * @extends \IteratorAggregate<int,Member>
+ */
+interface Collection extends \IteratorAggregate
+{
+}
+
+/**
+ * A member of a collection. Also a collection containing only itself.
+ *
+ * In the real world, this would contain additional methods.
+ */
+interface Member extends Collection
+{
+
+}
+
+class MemberImpl implements Member
+{
+
+	/**
+	 * @return \Iterator<int,Member>
+	 */
+	public function getIterator(): \Iterator
+	{
+		return new \ArrayIterator([$this]);
+	}
+
+}
+
+class CollectionImpl implements Collection
+{
+
+	/**
+	 * @var array<int,Member>
+	 */
+	private $members;
+
+	public function __construct(Member ...$members)
+	{
+		$this->members = $members;
+	}
+
+	/**
+	 * @return Member
+	 */
+	public function getMember(): Member
+	{
+		return new MemberImpl();
+	}
+
+	/**
+	 * @return \Iterator<int,Member>
+	 */
+	public function getIterator(): \Iterator
+	{
+		return new \ArrayIterator($this->members);
+	}
+
+}