From 76175021180bcd4316aac0a16865c016b6447ed7 Mon Sep 17 00:00:00 2001
From: Rodrigo Pedra Brum <rodrigo.pedra@gmail.com>
Date: Tue, 22 Apr 2025 18:00:57 -0300
Subject: [PATCH 1/2] ensure related models is iterable

---
 .../Database/Eloquent/Concerns/HasRelationships.php         | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/src/Illuminate/Database/Eloquent/Concerns/HasRelationships.php b/src/Illuminate/Database/Eloquent/Concerns/HasRelationships.php
index 6893c1284e3f..fc211e179a53 100644
--- a/src/Illuminate/Database/Eloquent/Concerns/HasRelationships.php
+++ b/src/Illuminate/Database/Eloquent/Concerns/HasRelationships.php
@@ -1086,7 +1086,11 @@ public function relationLoaded($key)
         }
 
         if ($nestedRelation !== null) {
-            foreach ($this->$relation as $related) {
+            $relatedModels = is_iterable($relatedModels = $this->$relation)
+                ? $relatedModels
+                : [$relatedModels];
+
+            foreach ($relatedModels as $related) {
                 if (! $related->relationLoaded($nestedRelation)) {
                     return false;
                 }

From 554facae877ac8edc5dd6f49e2c0dec790c73582 Mon Sep 17 00:00:00 2001
From: Rodrigo Pedra Brum <rodrigo.pedra@gmail.com>
Date: Wed, 23 Apr 2025 03:38:10 -0300
Subject: [PATCH 2/2] add test case

---
 .../Database/EloquentModelRelationLoadedTest.php | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/tests/Integration/Database/EloquentModelRelationLoadedTest.php b/tests/Integration/Database/EloquentModelRelationLoadedTest.php
index 06a0a740d3ba..548a50d11957 100644
--- a/tests/Integration/Database/EloquentModelRelationLoadedTest.php
+++ b/tests/Integration/Database/EloquentModelRelationLoadedTest.php
@@ -119,6 +119,22 @@ public function testWhenChildRecursiveRelationIsLoaded()
         $this->assertTrue($model->relationLoaded('twos.threes'));
         $this->assertTrue($model->relationLoaded('twos.threes.one'));
     }
+
+    public function testWhenParentRelationIsASingleInstance()
+    {
+        $one = One::query()->create();
+        $two = $one->twos()->create();
+        $three = $two->threes()->create();
+
+        $model = Three::query()
+            ->with('two.one')
+            ->find($three->id);
+
+        $this->assertTrue($model->relationLoaded('two'));
+        $this->assertTrue($model->two->is($two));
+        $this->assertTrue($model->relationLoaded('two.one'));
+        $this->assertTrue($model->two->one->is($one));
+    }
 }
 
 class One extends Model