diff --git a/src/Psalm/Checker/Statements/Expression/CallChecker.php b/src/Psalm/Checker/Statements/Expression/CallChecker.php
index 802a14eba..2ae930307 100644
--- a/src/Psalm/Checker/Statements/Expression/CallChecker.php
+++ b/src/Psalm/Checker/Statements/Expression/CallChecker.php
@@ -986,6 +986,13 @@ class CallChecker
                     $return_type_candidate = Type::getString();
                 } elseif (FunctionChecker::inCallMap($cased_method_id)) {
                     $return_type_candidate = FunctionChecker::getReturnTypeFromCallMap($method_id);
+
+                    $return_type_candidate = ExpressionChecker::fleshOutType(
+                        $project_checker,
+                        $return_type_candidate,
+                        $fq_class_name,
+                        $method_id
+                    );
                 } else {
                     if (MethodChecker::checkMethodVisibility(
                         $method_id,
diff --git a/tests/MethodCallTest.php b/tests/MethodCallTest.php
index 6bf0a3c97..8b23227fb 100644
--- a/tests/MethodCallTest.php
+++ b/tests/MethodCallTest.php
@@ -74,9 +74,12 @@ class MethodCallTest extends TestCase
                     final class MyDate extends DateTimeImmutable {}
 
                     $today = new MyDate();
-                    $yesterday = $today->sub(new DateInterval("P1D"));',
+                    $yesterday = $today->sub(new DateInterval("P1D"));
+
+                    $b = (new DateTimeImmutable())->modify("+3 hours");',
                 'assertions' => [
                     '$yesterday' => 'MyDate',
+                    '$b' => 'DateTimeImmutable',
                 ],
             ],
         ];