diff --git a/src/Util/ClassSourceManipulator.php b/src/Util/ClassSourceManipulator.php
index f4bc45a40..fb87c57e8 100644
--- a/src/Util/ClassSourceManipulator.php
+++ b/src/Util/ClassSourceManipulator.php
@@ -232,6 +232,12 @@ public function addGetter(string $propertyName, $returnType, bool $isReturnTypeN
     public function addSetter(string $propertyName, $type, bool $isNullable, array $commentLines = [])
     {
         $builder = $this->createSetterNodeBuilder($propertyName, $type, $isNullable, $commentLines);
+        $builder->addStmt(
+            new Node\Stmt\Expression(new Node\Expr\Assign(
+                new Node\Expr\PropertyFetch(new Node\Expr\Variable('this'), $propertyName),
+                new Node\Expr\Variable($propertyName)
+            ))
+        );
         $this->makeMethodFluent($builder);
         $this->addMethod($builder->getNode());
     }
@@ -411,13 +417,6 @@ private function createSetterNodeBuilder(string $propertyName, $type, bool $isNu
         }
         $setterNodeBuilder->addParam($paramBuilder->getNode());
 
-        $setterNodeBuilder->addStmt(
-            new Node\Stmt\Expression(new Node\Expr\Assign(
-                new Node\Expr\PropertyFetch(new Node\Expr\Variable('this'), $propertyName),
-                new Node\Expr\Variable($propertyName)
-            ))
-        );
-
         return $setterNodeBuilder;
     }
 
@@ -538,11 +537,15 @@ private function addSingularRelation(BaseRelation $relation)
         // OneToOne is the only "singular" relation type that
         // may be the inverse side
         if ($relation instanceof RelationOneToOne && !$relation->isOwning()) {
-            $setterNodeBuilder->addStmt($this->createBlankLineNode(self::CONTEXT_CLASS_METHOD));
-
             $this->addNodesToSetOtherSideOfOneToOne($relation, $setterNodeBuilder);
         }
 
+        $setterNodeBuilder->addStmt(
+            new Node\Stmt\Expression(new Node\Expr\Assign(
+                new Node\Expr\PropertyFetch(new Node\Expr\Variable('this'), $relation->getPropertyName()),
+                new Node\Expr\Variable($relation->getPropertyName())
+            ))
+        );
         $this->makeMethodFluent($setterNodeBuilder);
         $this->addMethod($setterNodeBuilder->getNode());
     }
@@ -1213,50 +1216,74 @@ private function addNodesToSetOtherSideOfOneToOne(RelationOneToOne $relation, Bu
                 )),
             ];
             $setterNodeBuilder->addStmt($ifNode);
+            $setterNodeBuilder->addStmt($this->createBlankLineNode(self::CONTEXT_CLASS_METHOD));
 
             return;
         }
 
         // at this point, we know the relation is nullable
         $setterNodeBuilder->addStmt($this->createSingleLineCommentNode(
-            'set (or unset) the owning side of the relation if necessary',
+            'unset the owning side of the relation if necessary',
             self::CONTEXT_CLASS_METHOD
         ));
 
-        $varName = 'new'.ucfirst($relation->getTargetPropertyName());
-        // $newUserProfile = null === $user ? null : $this;
-        $setterNodeBuilder->addStmt(
-            new Node\Stmt\Expression(new Node\Expr\Assign(
-                new Node\Expr\Variable($varName),
-                new Node\Expr\Ternary(
-                    new Node\Expr\BinaryOp\Identical(
-                        $this->createNullConstant(),
-                        new Node\Expr\Variable($relation->getPropertyName())
-                    ),
-                    $this->createNullConstant(),
-                    new Node\Expr\Variable('this')
-                )
-            ))
-        );
-
-        // if ($user->getUserProfile() !== $newUserProfile) {
-        $ifNode = new Node\Stmt\If_(new Node\Expr\BinaryOp\NotIdentical(
-            new Node\Expr\MethodCall(
+        // if ($user !== null && $user->getUserProfile() !== $this)
+        $ifNode = new Node\Stmt\If_(new Node\Expr\BinaryOp\BooleanAnd(
+            new Node\Expr\BinaryOp\Identical(
                 new Node\Expr\Variable($relation->getPropertyName()),
-                $relation->getTargetGetterMethodName()
+                $this->createNullConstant()
             ),
-            new Node\Expr\Variable($varName)
+            new Node\Expr\BinaryOp\NotIdentical(
+                new Node\Expr\PropertyFetch(
+                    new Node\Expr\Variable('this'),
+                    $relation->getPropertyName()
+                ),
+                $this->createNullConstant()
+            )
         ));
+        $ifNode->stmts = [
+            // $this->user->setUserProfile(null)
+            new Node\Stmt\Expression(new Node\Expr\MethodCall(
+                new Node\Expr\PropertyFetch(
+                    new Node\Expr\Variable('this'),
+                    $relation->getPropertyName()
+                ),
+                $relation->getTargetSetterMethodName(),
+                [new Node\Arg($this->createNullConstant())]
+            )),
+        ];
+        $setterNodeBuilder->addStmt($ifNode);
 
-        // $user->setUserProfile($newUserProfile);
+        $setterNodeBuilder->addStmt($this->createBlankLineNode(self::CONTEXT_CLASS_METHOD));
+        $setterNodeBuilder->addStmt($this->createSingleLineCommentNode(
+            'set the owning side of the relation if necessary',
+            self::CONTEXT_CLASS_METHOD
+        ));
+
+        // if ($user === null && $this->user !== null)
+        $ifNode = new Node\Stmt\If_(new Node\Expr\BinaryOp\BooleanAnd(
+            new Node\Expr\BinaryOp\NotIdentical(
+                new Node\Expr\Variable($relation->getPropertyName()),
+                $this->createNullConstant()
+            ),
+            new Node\Expr\BinaryOp\NotIdentical(
+                new Node\Expr\MethodCall(
+                    new Node\Expr\Variable($relation->getPropertyName()),
+                    $relation->getTargetGetterMethodName()
+                ),
+                new Node\Expr\Variable('this')
+            )
+        ));
         $ifNode->stmts = [
             new Node\Stmt\Expression(new Node\Expr\MethodCall(
                 new Node\Expr\Variable($relation->getPropertyName()),
                 $relation->getTargetSetterMethodName(),
-                [new Node\Arg(new Node\Expr\Variable($varName))]
+                [new Node\Arg(new Node\Expr\Variable('this'))]
             )),
         ];
         $setterNodeBuilder->addStmt($ifNode);
+
+        $setterNodeBuilder->addStmt($this->createBlankLineNode(self::CONTEXT_CLASS_METHOD));
     }
 
     private function methodExists(string $methodName): bool
diff --git a/tests/Doctrine/fixtures/expected_overwrite/src/Entity/User.php b/tests/Doctrine/fixtures/expected_overwrite/src/Entity/User.php
index 91fdbcee3..c812013bd 100644
--- a/tests/Doctrine/fixtures/expected_overwrite/src/Entity/User.php
+++ b/tests/Doctrine/fixtures/expected_overwrite/src/Entity/User.php
@@ -51,14 +51,18 @@ public function customMethod()
 
     public function setUserProfile(?UserProfile $userProfile): self
     {
-        $this->userProfile = $userProfile;
+        // unset the owning side of the relation if necessary
+        if ($userProfile === null && $this->userProfile !== null) {
+            $this->userProfile->setUser(null);
+        }
 
-        // set (or unset) the owning side of the relation if necessary
-        $newUser = null === $userProfile ? null : $this;
-        if ($userProfile->getUser() !== $newUser) {
-            $userProfile->setUser($newUser);
+        // set the owning side of the relation if necessary
+        if ($userProfile !== null && $userProfile->getUser() !== $this) {
+            $userProfile->setUser($this);
         }
 
+        $this->userProfile = $userProfile;
+
         return $this;
     }
 
diff --git a/tests/Util/fixtures/add_one_to_one_relation/UserProfile_simple_inverse.php b/tests/Util/fixtures/add_one_to_one_relation/UserProfile_simple_inverse.php
index 016967a30..6ca0ec0d6 100644
--- a/tests/Util/fixtures/add_one_to_one_relation/UserProfile_simple_inverse.php
+++ b/tests/Util/fixtures/add_one_to_one_relation/UserProfile_simple_inverse.php
@@ -33,14 +33,18 @@ public function getUser(): ?User
 
     public function setUser(?User $user): self
     {
-        $this->user = $user;
+        // unset the owning side of the relation if necessary
+        if ($user === null && $this->user !== null) {
+            $this->user->setUserProfile(null);
+        }
 
-        // set (or unset) the owning side of the relation if necessary
-        $newUserProfile = null === $user ? null : $this;
-        if ($user->getUserProfile() !== $newUserProfile) {
-            $user->setUserProfile($newUserProfile);
+        // set the owning side of the relation if necessary
+        if ($user !== null && $user->getUserProfile() !== $this) {
+            $user->setUserProfile($this);
         }
 
+        $this->user = $user;
+
         return $this;
     }
 }
diff --git a/tests/Util/fixtures/add_one_to_one_relation/UserProfile_simple_inverse_not_nullable.php b/tests/Util/fixtures/add_one_to_one_relation/UserProfile_simple_inverse_not_nullable.php
index 45c80a7fc..e52100ee3 100644
--- a/tests/Util/fixtures/add_one_to_one_relation/UserProfile_simple_inverse_not_nullable.php
+++ b/tests/Util/fixtures/add_one_to_one_relation/UserProfile_simple_inverse_not_nullable.php
@@ -33,13 +33,13 @@ public function getUser(): ?User
 
     public function setUser(User $user): self
     {
-        $this->user = $user;
-
         // set the owning side of the relation if necessary
         if ($user->getUserProfile() !== $this) {
             $user->setUserProfile($this);
         }
 
+        $this->user = $user;
+
         return $this;
     }
 }