diff --git a/src/collections/deserialize/index.ts b/src/collections/deserialize/index.ts
index 588c2642..9cf81d6f 100644
--- a/src/collections/deserialize/index.ts
+++ b/src/collections/deserialize/index.ts
@@ -329,7 +329,7 @@ export class Deserialize {
     if (value.blobValue !== undefined) return value.blobValue;
     if (value.geoValue !== undefined) return value.geoValue;
     if (value.phoneValue !== undefined) return value.phoneValue;
-    if (value.nullValue !== undefined) return undefined;
+    if (value.nullValue !== undefined) return null;
     throw new WeaviateDeserializationError(`Unknown value type: ${JSON.stringify(value, null, 2)}`);
   }