diff --git a/crates/presentation/src/handlers/diary.rs b/crates/presentation/src/handlers/diary.rs
index c71cf29..fd88571 100644
--- a/crates/presentation/src/handlers/diary.rs
+++ b/crates/presentation/src/handlers/diary.rs
@@ -1,5 +1,6 @@
 use axum::{
     Form, Json,
+    body::Body,
     extract::{Extension, Path, Query, State},
     http::StatusCode,
     response::{IntoResponse, Redirect},
@@ -147,30 +148,23 @@ pub async fn export_diary(
         user_id: user.0.value(),
         format,
     };
-    match export_diary_uc::execute(
+    let stream = export_diary_uc::execute(
         &state.app_ctx.repos.diary,
         &state.app_ctx.services.diary_exporter,
         query,
+    );
+    (
+        StatusCode::OK,
+        [
+            (axum::http::header::CONTENT_TYPE, content_type.to_string()),
+            (
+                axum::http::header::CONTENT_DISPOSITION,
+                format!("attachment; filename=\"{}\"", filename),
+            ),
+        ],
+        Body::from_stream(stream),
     )
-    .await
-    {
-        Ok(bytes) => (
-            StatusCode::OK,
-            [
-                (axum::http::header::CONTENT_TYPE, content_type.to_string()),
-                (
-                    axum::http::header::CONTENT_DISPOSITION,
-                    format!("attachment; filename=\"{}\"", filename),
-                ),
-            ],
-            bytes,
-        )
-            .into_response(),
-        Err(e) => {
-            tracing::error!("export error: {:?}", e);
-            StatusCode::INTERNAL_SERVER_ERROR.into_response()
-        }
-    }
+        .into_response()
 }
 
 #[utoipa::path(
@@ -314,27 +308,23 @@ pub async fn get_export_html(
         user_id: user_id.value(),
         format,
     };
-    match export_diary_uc::execute(
+    let stream = export_diary_uc::execute(
         &state.app_ctx.repos.diary,
         &state.app_ctx.services.diary_exporter,
         query,
+    );
+    (
+        StatusCode::OK,
+        [
+            (axum::http::header::CONTENT_TYPE, content_type.to_string()),
+            (
+                axum::http::header::CONTENT_DISPOSITION,
+                format!("attachment; filename=\"{}\"", filename),
+            ),
+        ],
+        Body::from_stream(stream),
     )
-    .await
-    {
-        Ok(bytes) => (
-            StatusCode::OK,
-            [
-                (axum::http::header::CONTENT_TYPE, content_type.to_string()),
-                (
-                    axum::http::header::CONTENT_DISPOSITION,
-                    format!("attachment; filename=\"{}\"", filename),
-                ),
-            ],
-            bytes,
-        )
-            .into_response(),
-        Err(e) => crate::errors::domain_error_response(e),
-    }
+        .into_response()
 }
 
 pub async fn get_activity_feed_html(
diff --git a/crates/presentation/src/tests/extractors.rs b/crates/presentation/src/tests/extractors.rs
index e1bb397..060b343 100644
--- a/crates/presentation/src/tests/extractors.rs
+++ b/crates/presentation/src/tests/extractors.rs
@@ -120,6 +120,12 @@ impl DiaryRepository for Panic {
     async fn get_user_history(&self, _: &UserId) -> Result<Vec<DiaryEntry>, DomainError> {
         panic!()
     }
+    fn stream_user_history(
+        &self,
+        _: UserId,
+    ) -> futures::stream::BoxStream<'static, Result<DiaryEntry, DomainError>> {
+        panic!()
+    }
     async fn get_movie_stats(
         &self,
         _: &MovieId,
@@ -379,14 +385,17 @@ impl domain::ports::MovieProfileRepository for Panic {
         Ok(vec![])
     }
 }
-#[async_trait::async_trait]
 impl domain::ports::DiaryExporter for Panic {
-    async fn serialize_entries(
+    fn stream_entries(
         &self,
-        _: &[domain::models::DiaryEntry],
-        _: domain::models::ExportFormat,
-    ) -> Result<Vec<u8>, domain::errors::DomainError> {
-        panic!()
+        _stream: futures::stream::BoxStream<
+            'static,
+            Result<domain::models::DiaryEntry, domain::errors::DomainError>,
+        >,
+        _format: domain::models::ExportFormat,
+    ) -> futures::stream::BoxStream<'static, Result<bytes::Bytes, domain::errors::DomainError>>
+    {
+        panic!("Panic DiaryExporter called")
     }
 }
 
diff --git a/crates/presentation/tests/api_test.rs b/crates/presentation/tests/api_test.rs
index fe62d27..d757585 100644
--- a/crates/presentation/tests/api_test.rs
+++ b/crates/presentation/tests/api_test.rs
@@ -165,14 +165,16 @@ impl domain::ports::UserProfileFieldsRepository for PanicProfileFields {
 }
 
 struct PanicExporter;
-#[async_trait]
 impl domain::ports::DiaryExporter for PanicExporter {
-    async fn serialize_entries(
+    fn stream_entries(
         &self,
-        _: &[domain::models::DiaryEntry],
-        _: domain::models::ExportFormat,
-    ) -> Result<Vec<u8>, DomainError> {
-        panic!()
+        _stream: futures::stream::BoxStream<
+            'static,
+            Result<domain::models::DiaryEntry, DomainError>,
+        >,
+        _format: domain::models::ExportFormat,
+    ) -> futures::stream::BoxStream<'static, Result<bytes::Bytes, DomainError>> {
+        panic!("PanicExporter::stream_entries")
     }
 }