diff --git a/client/src/client.rs b/client/src/client.rs
index 5031f4d..0e587c1 100644
--- a/client/src/client.rs
+++ b/client/src/client.rs
@@ -11,8 +11,9 @@ use std::{
     time::Duration,
 };
 
-use clusterizer_api::client::ApiClient;
+use clusterizer_api::{client::ApiClient, result::ApiError};
 use clusterizer_common::{
+    errors::SubmitResultError,
     records::{
         Platform, PlatformFilter, Project, ProjectFilter, ProjectVersion, ProjectVersionFilter,
         Task,
@@ -223,7 +224,10 @@ impl ClusterizerClient {
             exit_code: output.status.code(),
         };
 
-        self.client.submit_result(task_id, &request).await?;
+        match self.client.submit_result(task_id, &request).await {
+            Err(ApiError::Specific(SubmitResultError::AssignmentExpired)) => {}
+            result => result?,
+        };
 
         Ok(Return::SubmitResult)
     }
diff --git a/common/src/errors/submit_result_error.rs b/common/src/errors/submit_result_error.rs
index 8e6992c..b8ec6eb 100644
--- a/common/src/errors/submit_result_error.rs
+++ b/common/src/errors/submit_result_error.rs
@@ -7,4 +7,8 @@ pub enum SubmitResultError {
     InvalidTask,
     #[error("already exists")]
     AlreadyExists,
+    #[error("assignment canceled")]
+    AssignmentCanceled,
+    #[error("assignment expired")]
+    AssignmentExpired,
 }
diff --git a/common/src/types/assignment_state.rs b/common/src/types/assignment_state.rs
index 9cbe8ec..d5336bd 100644
--- a/common/src/types/assignment_state.rs
+++ b/common/src/types/assignment_state.rs
@@ -1,6 +1,6 @@
 use serde::{Deserialize, Serialize};
 
-#[derive(Clone, Hash, Debug, Serialize, Deserialize)]
+#[derive(Copy, Clone, Eq, PartialEq, Ord, PartialOrd, Hash, Debug, Serialize, Deserialize)]
 #[cfg_attr(feature = "sqlx", derive(sqlx::Type))]
 #[cfg_attr(
     feature = "sqlx",
diff --git a/server/.sqlx/query-1260e6fd3c1f30f651d1f86bf86af3351a6629a942b732ccf6740b2e683eedae.json b/server/.sqlx/query-1260e6fd3c1f30f651d1f86bf86af3351a6629a942b732ccf6740b2e683eedae.json
new file mode 100644
index 0000000..4e370e3
--- /dev/null
+++ b/server/.sqlx/query-1260e6fd3c1f30f651d1f86bf86af3351a6629a942b732ccf6740b2e683eedae.json
@@ -0,0 +1,68 @@
+{
+  "db_name": "PostgreSQL",
+  "query": "\n        SELECT\n            *\n        FROM\n            assignments\n        WHERE\n            task_id = $1\n            AND user_id = $2\n        FOR UPDATE\n        ",
+  "describe": {
+    "columns": [
+      {
+        "ordinal": 0,
+        "name": "id",
+        "type_info": "Int8"
+      },
+      {
+        "ordinal": 1,
+        "name": "created_at",
+        "type_info": "Timestamptz"
+      },
+      {
+        "ordinal": 2,
+        "name": "deadline_at",
+        "type_info": "Timestamptz"
+      },
+      {
+        "ordinal": 3,
+        "name": "task_id",
+        "type_info": "Int8"
+      },
+      {
+        "ordinal": 4,
+        "name": "user_id",
+        "type_info": "Int8"
+      },
+      {
+        "ordinal": 5,
+        "name": "state",
+        "type_info": {
+          "Custom": {
+            "name": "assignment_state",
+            "kind": {
+              "Enum": [
+                "init",
+                "canceled",
+                "expired",
+                "submitted",
+                "valid",
+                "invalid",
+                "inconclusive"
+              ]
+            }
+          }
+        }
+      }
+    ],
+    "parameters": {
+      "Left": [
+        "Int8",
+        "Int8"
+      ]
+    },
+    "nullable": [
+      false,
+      false,
+      false,
+      false,
+      false,
+      false
+    ]
+  },
+  "hash": "1260e6fd3c1f30f651d1f86bf86af3351a6629a942b732ccf6740b2e683eedae"
+}
diff --git a/server/.sqlx/query-fb96b317421697e972b3098b2ecc82113138a82a0f1c4c08dbb7f827e5150b97.json b/server/.sqlx/query-fb96b317421697e972b3098b2ecc82113138a82a0f1c4c08dbb7f827e5150b97.json
deleted file mode 100644
index ac51bb7..0000000
--- a/server/.sqlx/query-fb96b317421697e972b3098b2ecc82113138a82a0f1c4c08dbb7f827e5150b97.json
+++ /dev/null
@@ -1,23 +0,0 @@
-{
-  "db_name": "PostgreSQL",
-  "query": "\n        SELECT\n            id \"id: Id<Assignment>\"\n        FROM\n            assignments\n        WHERE\n            task_id = $1\n            AND user_id = $2\n            AND state != 'canceled'\n        FOR UPDATE\n        ",
-  "describe": {
-    "columns": [
-      {
-        "ordinal": 0,
-        "name": "id: Id<Assignment>",
-        "type_info": "Int8"
-      }
-    ],
-    "parameters": {
-      "Left": [
-        "Int8",
-        "Int8"
-      ]
-    },
-    "nullable": [
-      false
-    ]
-  },
-  "hash": "fb96b317421697e972b3098b2ecc82113138a82a0f1c4c08dbb7f827e5150b97"
-}
diff --git a/server/src/routes/submit_result.rs b/server/src/routes/submit_result.rs
index ebb1ef5..c628f90 100644
--- a/server/src/routes/submit_result.rs
+++ b/server/src/routes/submit_result.rs
@@ -11,7 +11,7 @@ use clusterizer_common::{
 
 use crate::{
     auth::Auth,
-    result::{AppResult, ResultExt},
+    result::{AppError, AppResult, ResultExt},
     state::AppState,
     util,
 };
@@ -24,16 +24,16 @@ pub async fn submit_result(
 ) -> AppResult<(), SubmitResultError> {
     let mut tx = state.pool.begin().await?;
 
-    let assignment_id = sqlx::query_scalar_unchecked!(
+    let assignment = sqlx::query_as_unchecked!(
+        Assignment,
         r#"
         SELECT
-            id "id: Id<Assignment>"
+            *
         FROM
             assignments
         WHERE
             task_id = $1
             AND user_id = $2
-            AND state != 'canceled'
         FOR UPDATE
         "#,
         task_id,
@@ -43,6 +43,14 @@ pub async fn submit_result(
     .await
     .map_not_found(SubmitResultError::InvalidTask)?;
 
+    if assignment.state == AssignmentState::Canceled {
+        Err(AppError::Specific(SubmitResultError::AssignmentCanceled))?;
+    }
+
+    if assignment.state == AssignmentState::Expired {
+        Err(AppError::Specific(SubmitResultError::AssignmentExpired))?;
+    }
+
     sqlx::query_unchecked!(
         r#"
         INSERT INTO results (
@@ -57,7 +65,7 @@ pub async fn submit_result(
             $4
         )
         "#,
-        assignment_id,
+        assignment.id,
         request.stdout,
         request.stderr,
         request.exit_code,
@@ -66,7 +74,7 @@ pub async fn submit_result(
     .await
     .map_unique_violation(SubmitResultError::AlreadyExists)?;
 
-    util::set_assignment_state(&[assignment_id], AssignmentState::Submitted)
+    util::set_assignment_state(&[assignment.id], AssignmentState::Submitted)
         .execute(&mut *tx)
         .await?;