diff --git a/dispatcher/backend/src/common/schemas/offliners/zimit.py b/dispatcher/backend/src/common/schemas/offliners/zimit.py
index 233fa487..b359a6f4 100644
--- a/dispatcher/backend/src/common/schemas/offliners/zimit.py
+++ b/dispatcher/backend/src/common/schemas/offliners/zimit.py
@@ -1,10 +1,11 @@
 from marshmallow import fields, validate
 
-from common.schemas import SerializableSchema, String, StringEnum
+from common.schemas import LongString, SerializableSchema, String, StringEnum
 from common.schemas.fields import (
     validate_output,
     validate_zim_description,
     validate_zim_filename,
+    validate_zim_longdescription,
     validate_zim_title,
 )
 
@@ -185,6 +186,15 @@ class Meta:
         validate=validate_zim_description,
     )
 
+    long_description = LongString(
+        metadata={
+            "label": "Long description",
+            "description": "Optional long description for your ZIM",
+        },
+        validate=validate_zim_longdescription,
+        data_key="long-description",
+    )
+
     favicon = fields.Url(
         metadata={
             "label": "Illustration",