diff --git a/src/Util/ClassSourceManipulator.php b/src/Util/ClassSourceManipulator.php
index 7d48ee63e..0c9687891 100644
--- a/src/Util/ClassSourceManipulator.php
+++ b/src/Util/ClassSourceManipulator.php
@@ -531,12 +531,14 @@ private function addSingularRelation(BaseRelation $relation): void
         $setterNodeBuilder = $this->createSetterNodeBuilder(
             $relation->getPropertyName(),
             $typeHint,
-            // make the type-hint nullable always for ManyToOne to allow the owning
-            // side to be set to null, which is needed for orphanRemoval
-            // (specifically: when you set the inverse side, the generated
-            // code will *also* set the owning side to null - so it needs to be allowed)
-            // e.g. $userAvatarPhoto->setUser(null);
-            $relation instanceof RelationOneToOne ? $relation->isNullable() : true
+            // A ManyToOne setter must stay nullable as soon as the relation maps an
+            // inverse side: the collection remove*() generated on that side sets the
+            // owning side back to null (orphanRemoval), e.g. $userAvatarPhoto->setUser(null);
+            // so null must be allowed there. A non-nullable, *unidirectional* ManyToOne
+            // has no such code path, so its setter can use a strict, non-nullable type-hint.
+            $relation instanceof RelationOneToOne
+                ? $relation->isNullable()
+                : ($relation->isNullable() || $relation->getMapInverseRelation())
         );
 
         // set the *owning* side of the relation
diff --git a/tests/Util/ClassSourceManipulatorTest.php b/tests/Util/ClassSourceManipulatorTest.php
index be9a3d5d0..700f4180e 100644
--- a/tests/Util/ClassSourceManipulatorTest.php
+++ b/tests/Util/ClassSourceManipulatorTest.php
@@ -411,6 +411,20 @@ public static function getAddManyToOneRelationTests(): \Generator
                 isNullable: true,
             ),
         ];
+
+        // A non-nullable, unidirectional ManyToOne has no inverse remove*()
+        // setting the owning side back to null, so its setter can be strict.
+        yield 'many_to_one_not_nullable_no_inverse' => [
+            'User_simple.php',
+            'User_simple_not_nullable_no_inverse.php',
+            new RelationManyToOne(
+                propertyName: 'category',
+                targetClassName: \App\Entity\Category::class,
+                targetPropertyName: 'foods',
+                mapInverseRelation: false,
+                isOwning: true,
+            ),
+        ];
     }
 
     /**
diff --git a/tests/Util/fixtures/add_many_to_one_relation/User_simple_not_nullable_no_inverse.php b/tests/Util/fixtures/add_many_to_one_relation/User_simple_not_nullable_no_inverse.php
new file mode 100644
index 000000000..8bc2d455c
--- /dev/null
+++ b/tests/Util/fixtures/add_many_to_one_relation/User_simple_not_nullable_no_inverse.php
@@ -0,0 +1,35 @@
+<?php
+
+namespace App\Entity;
+
+use Doctrine\ORM\Mapping as ORM;
+
+#[ORM\Entity]
+class User
+{
+    #[ORM\Id]
+    #[ORM\GeneratedValue]
+    #[ORM\Column()]
+    private ?int $id = null;
+
+    #[ORM\ManyToOne]
+    #[ORM\JoinColumn(nullable: false)]
+    private ?Category $category = null;
+
+    public function getId(): ?int
+    {
+        return $this->id;
+    }
+
+    public function getCategory(): ?Category
+    {
+        return $this->category;
+    }
+
+    public function setCategory(Category $category): static
+    {
+        $this->category = $category;
+
+        return $this;
+    }
+}