diff --git a/src/Bundle/ChillDocStoreBundle/Service/Signature/Driver/BaseSigner/PdfSignedMessage.php b/src/Bundle/ChillDocStoreBundle/Service/Signature/Driver/BaseSigner/PdfSignedMessage.php
index 64ada47c7..3116e3b62 100644
--- a/src/Bundle/ChillDocStoreBundle/Service/Signature/Driver/BaseSigner/PdfSignedMessage.php
+++ b/src/Bundle/ChillDocStoreBundle/Service/Signature/Driver/BaseSigner/PdfSignedMessage.php
@@ -18,6 +18,7 @@ final readonly class PdfSignedMessage
 {
     public function __construct(
         public readonly int $signatureId,
-        public readonly string $content
+        public readonly int $signatureZoneIndex,
+        public readonly string $content,
     ) {}
 }
diff --git a/src/Bundle/ChillDocStoreBundle/Service/Signature/Driver/BaseSigner/PdfSignedMessageHandler.php b/src/Bundle/ChillDocStoreBundle/Service/Signature/Driver/BaseSigner/PdfSignedMessageHandler.php
index 5cb31de96..720bc000f 100644
--- a/src/Bundle/ChillDocStoreBundle/Service/Signature/Driver/BaseSigner/PdfSignedMessageHandler.php
+++ b/src/Bundle/ChillDocStoreBundle/Service/Signature/Driver/BaseSigner/PdfSignedMessageHandler.php
@@ -55,6 +55,7 @@ final readonly class PdfSignedMessageHandler implements MessageHandlerInterface
         $this->storedObjectManager->write($storedObject, $message->content);
 
         $signature->setState(EntityWorkflowSignatureStateEnum::SIGNED)->setStateDate($this->clock->now());
+        $signature->setZoneSignatureIndex($message->signatureZoneIndex);
         $this->entityManager->flush();
         $this->entityManager->clear();
     }
diff --git a/src/Bundle/ChillDocStoreBundle/Service/Signature/Driver/BaseSigner/PdfSignedMessageSerializer.php b/src/Bundle/ChillDocStoreBundle/Service/Signature/Driver/BaseSigner/PdfSignedMessageSerializer.php
index 4af4a9504..892b944b7 100644
--- a/src/Bundle/ChillDocStoreBundle/Service/Signature/Driver/BaseSigner/PdfSignedMessageSerializer.php
+++ b/src/Bundle/ChillDocStoreBundle/Service/Signature/Driver/BaseSigner/PdfSignedMessageSerializer.php
@@ -40,7 +40,7 @@ final readonly class PdfSignedMessageSerializer implements SerializerInterface
             throw new MessageDecodingFailedException('Invalid character found in the base64 encoded content');
         }
 
-        $message = new PdfSignedMessage($decoded['signatureId'], $content);
+        $message = new PdfSignedMessage($decoded['signatureId'], $decoded['signatureZoneIndex'], $content);
 
         return new Envelope($message);
     }
@@ -55,6 +55,7 @@ final readonly class PdfSignedMessageSerializer implements SerializerInterface
 
         $data = [
             'signatureId' => $message->signatureId,
+            'signatureZoneIndex' => $message->signatureZoneIndex,
             'content' => base64_encode($message->content),
         ];
 
diff --git a/src/Bundle/ChillDocStoreBundle/Tests/Service/Signature/Driver/BaseSigner/PdfSignedMessageHandlerTest.php b/src/Bundle/ChillDocStoreBundle/Tests/Service/Signature/Driver/BaseSigner/PdfSignedMessageHandlerTest.php
index eb2142175..471dc8f9a 100644
--- a/src/Bundle/ChillDocStoreBundle/Tests/Service/Signature/Driver/BaseSigner/PdfSignedMessageHandlerTest.php
+++ b/src/Bundle/ChillDocStoreBundle/Tests/Service/Signature/Driver/BaseSigner/PdfSignedMessageHandlerTest.php
@@ -57,9 +57,10 @@ class PdfSignedMessageHandlerTest extends TestCase
 
         // we simply call the handler. The mocked StoredObjectManager will check that the "write" method is invoked once
         // with the content "1234"
-        $handler(new PdfSignedMessage(10, $expectedContent));
+        $handler(new PdfSignedMessage(10, 99, $expectedContent));
 
         self::assertEquals('signed', $signature->getState()->value);
+        self::assertEquals(99, $signature->getZoneSignatureIndex());
     }
 
     private function buildSignatureRepository(EntityWorkflowStepSignature $signature): EntityWorkflowStepSignatureRepository
diff --git a/src/Bundle/ChillDocStoreBundle/Tests/Service/Signature/Driver/BaseSigner/PdfSignedMessageSerializerTest.php b/src/Bundle/ChillDocStoreBundle/Tests/Service/Signature/Driver/BaseSigner/PdfSignedMessageSerializerTest.php
index d9d600254..1321390f5 100644
--- a/src/Bundle/ChillDocStoreBundle/Tests/Service/Signature/Driver/BaseSigner/PdfSignedMessageSerializerTest.php
+++ b/src/Bundle/ChillDocStoreBundle/Tests/Service/Signature/Driver/BaseSigner/PdfSignedMessageSerializerTest.php
@@ -26,7 +26,7 @@ class PdfSignedMessageSerializerTest extends TestCase
     public function testDecode(): void
     {
         $asString = <<<'JSON'
-            {"signatureId": 0, "content": "dGVzdAo="}
+            {"signatureId": 0, "signatureZoneIndex": 10, "content": "dGVzdAo="}
             JSON;
 
         $actual = $this->buildSerializer()->decode(['body' => $asString]);
@@ -36,12 +36,13 @@ class PdfSignedMessageSerializerTest extends TestCase
         self::assertInstanceOf(PdfSignedMessage::class, $message);
         self::assertEquals("test\n", $message->content);
         self::assertEquals(0, $message->signatureId);
+        self::assertEquals(10, $message->signatureZoneIndex);
     }
 
     public function testEncode(): void
     {
         $envelope = new Envelope(
-            new PdfSignedMessage(0, "test\n")
+            new PdfSignedMessage(0, 10, "test\n")
         );
 
         $actual = $this->buildSerializer()->encode($envelope);
@@ -52,7 +53,7 @@ class PdfSignedMessageSerializerTest extends TestCase
         self::assertEquals([], $actual['headers']);
 
         self::assertEquals(<<<'JSON'
-                {"signatureId":0,"content":"dGVzdAo="}
+                {"signatureId":0,"signatureZoneIndex":10,"content":"dGVzdAo="}
                 JSON, $actual['body']);
     }