diff --git a/deepwell/src/services/file/structs.rs b/deepwell/src/services/file/structs.rs
index 14e2ec6db0..d5b7d3ba67 100644
--- a/deepwell/src/services/file/structs.rs
+++ b/deepwell/src/services/file/structs.rs
@@ -64,7 +64,11 @@ pub struct GetFileOutput {
 
     #[serde(with = "time::serde::rfc3339")]
     pub file_created_at: OffsetDateTime,
+
+    #[serde(with = "time::serde::rfc3339::option")]
     pub file_updated_at: Option<OffsetDateTime>,
+
+    #[serde(with = "time::serde::rfc3339::option")]
     pub file_deleted_at: Option<OffsetDateTime>,
     pub page_id: i64,
     pub revision_id: i64,
diff --git a/deepwell/src/services/link/structs.rs b/deepwell/src/services/link/structs.rs
index 4360fe6ef1..31db6ad145 100644
--- a/deepwell/src/services/link/structs.rs
+++ b/deepwell/src/services/link/structs.rs
@@ -91,6 +91,8 @@ pub struct GetLinksExternalToOutput {
 pub struct ToExternalLink {
     #[serde(with = "time::serde::rfc3339")]
     pub created_at: OffsetDateTime,
+
+    #[serde(with = "time::serde::rfc3339::option")]
     pub updated_at: Option<OffsetDateTime>,
     pub page_id: i64,
     pub count: i32,
diff --git a/deepwell/src/services/page/structs.rs b/deepwell/src/services/page/structs.rs
index 59c002a40b..ac666f029e 100644
--- a/deepwell/src/services/page/structs.rs
+++ b/deepwell/src/services/page/structs.rs
@@ -95,7 +95,11 @@ pub struct GetPageOutput {
 
     #[serde(with = "time::serde::rfc3339")]
     pub page_created_at: OffsetDateTime,
+
+    #[serde(with = "time::serde::rfc3339::option")]
     pub page_updated_at: Option<OffsetDateTime>,
+
+    #[serde(with = "time::serde::rfc3339::option")]
     pub page_deleted_at: Option<OffsetDateTime>,
     pub page_revision_count: i32,
     pub site_id: i64,
diff --git a/deepwell/src/services/page_revision/structs.rs b/deepwell/src/services/page_revision/structs.rs
index 3d7ecda521..b3d78f09f8 100644
--- a/deepwell/src/services/page_revision/structs.rs
+++ b/deepwell/src/services/page_revision/structs.rs
@@ -161,6 +161,8 @@ pub struct PageRevisionModelFiltered {
 
     #[serde(with = "time::serde::rfc3339")]
     pub created_at: OffsetDateTime,
+
+    #[serde(with = "time::serde::rfc3339::option")]
     pub updated_at: Option<OffsetDateTime>,
     pub from_wikidot: bool,
     pub revision_number: i32,