diff --git a/src/Bundle/ChillPersonBundle/Export/Aggregator/SocialWorkAggregators/ReferrerAggregator.php b/src/Bundle/ChillPersonBundle/Export/Aggregator/SocialWorkAggregators/ReferrerAggregator.php
index de0dceec3..c2ccbed8a 100644
--- a/src/Bundle/ChillPersonBundle/Export/Aggregator/SocialWorkAggregators/ReferrerAggregator.php
+++ b/src/Bundle/ChillPersonBundle/Export/Aggregator/SocialWorkAggregators/ReferrerAggregator.php
@@ -70,11 +70,19 @@ final readonly class ReferrerAggregator implements AggregatorInterface
 
     public function normalizeFormData(array $formData): array
     {
+        if (!array_key_exists('referrer_at', $formData)) {
+            return ['referrer_at' => (new RollingDate(RollingDate::T_TODAY))->normalize()];
+        }
+
         return ['referrer_at' => $formData['referrer_at']->normalize()];
     }
 
     public function denormalizeFormData(array $formData, int $fromVersion): array
     {
+        if (!array_key_exists('referrer_at', $formData)) {
+            return ['referrer_at' => new RollingDate(RollingDate::T_TODAY)];
+        }
+
         return ['referrer_at' => RollingDate::fromNormalized($formData['referrer_at'])];
     }
 
diff --git a/src/Bundle/ChillPersonBundle/Tests/Export/Aggregator/SocialWorkAggregators/ReferrerAggregatorTest.php b/src/Bundle/ChillPersonBundle/Tests/Export/Aggregator/SocialWorkAggregators/ReferrerAggregatorTest.php
index fd1f0ffc5..96ba94f62 100644
--- a/src/Bundle/ChillPersonBundle/Tests/Export/Aggregator/SocialWorkAggregators/ReferrerAggregatorTest.php
+++ b/src/Bundle/ChillPersonBundle/Tests/Export/Aggregator/SocialWorkAggregators/ReferrerAggregatorTest.php
@@ -60,4 +60,29 @@ final class ReferrerAggregatorTest extends AbstractAggregatorTest
                 ->from(AccompanyingPeriodWork::class, 'acpw'),
         ];
     }
+
+    /**
+     * A list of data to normalize.
+     *
+     * @return iterable{array}
+     */
+    public static function dataProviderFormDataToNormalize(): iterable
+    {
+        foreach (self::getFormData() as $data) {
+            yield [$data, 1, []];
+        }
+    }
+
+    /**
+     * @dataProvider dataProviderFormDataToNormalize
+     */
+    public function testDataNormalization(array $data, int $version, array $customAssert): void
+    {
+        $aggregator = $this->getAggregator();
+
+        $normalized = $aggregator->normalizeFormData($data);
+        $actual = $aggregator->denormalizeFormData($normalized, $version);
+
+        self::assertIsArray($actual);
+    }
 }