diff --git a/src/Reflection/Php/PhpMethodReflection.php b/src/Reflection/Php/PhpMethodReflection.php
index b141bcec7e..e9e8db3916 100644
--- a/src/Reflection/Php/PhpMethodReflection.php
+++ b/src/Reflection/Php/PhpMethodReflection.php
@@ -330,7 +330,13 @@ private function getNativeReturnType(): Type
 					return $this->nativeReturnType = new VoidType();
 				}
 				if ($name === '__tostring') {
-					return $this->nativeReturnType = new StringType();
+					return $this->nativeReturnType = $this->declaringClass->isBuiltin()
+						? new StringType()
+						: TypehintHelper::decideTypeFromReflection(
+							$returnType,
+							null,
+							$this->declaringClass,
+						);
 				}
 				if ($name === '__isset') {
 					return $this->nativeReturnType = new BooleanType();