diff --git a/crates/rustmail/src/commands/remove_reminder/slash_command/remove_reminder.rs b/crates/rustmail/src/commands/remove_reminder/slash_command/remove_reminder.rs
index 08f5327e..bf85e5a4 100644
--- a/crates/rustmail/src/commands/remove_reminder/slash_command/remove_reminder.rs
+++ b/crates/rustmail/src/commands/remove_reminder/slash_command/remove_reminder.rs
@@ -100,7 +100,15 @@ impl RegistrableCommand for RemoveReminderCommand {
             };
 
             let reminder = match get_reminder_by_id(reminder_id, pool).await {
-                Ok(Some(r)) => r,
+                Ok(Some(r)) => {
+                    if r.completed {
+                        return Err(ModmailError::Command(
+                            CommandError::ReminderAlreadyCompleted(reminder_id.to_string()),
+                        ));
+                    } else {
+                        r
+                    }
+                }
                 Ok(None) => {
                     return Err(ModmailError::Database(DatabaseError::NotFound(
                         "".to_string(),
diff --git a/crates/rustmail/src/commands/remove_reminder/text_command/remove_reminder.rs b/crates/rustmail/src/commands/remove_reminder/text_command/remove_reminder.rs
index 26a0c0fa..0323120a 100644
--- a/crates/rustmail/src/commands/remove_reminder/text_command/remove_reminder.rs
+++ b/crates/rustmail/src/commands/remove_reminder/text_command/remove_reminder.rs
@@ -38,7 +38,15 @@ pub async fn remove_reminder(
     };
 
     let reminder = match get_reminder_by_id(reminder_id as i64, pool).await {
-        Ok(Some(r)) => r,
+        Ok(Some(r)) => {
+            if r.completed {
+                return Err(ModmailError::Command(
+                    CommandError::ReminderAlreadyCompleted(reminder_id.to_string()),
+                ));
+            } else {
+                r
+            }
+        }
         Ok(None) => {
             return Err(ModmailError::Database(DatabaseError::NotFound(
                 "".to_string(),
diff --git a/crates/rustmail/src/errors/dictionary.rs b/crates/rustmail/src/errors/dictionary.rs
index 7b36506c..5855b189 100644
--- a/crates/rustmail/src/errors/dictionary.rs
+++ b/crates/rustmail/src/errors/dictionary.rs
@@ -286,6 +286,11 @@ impl DictionaryManager {
                         Some(params),
                     )
                 }
+                CommandError::ReminderAlreadyCompleted(reminder_id) => {
+                    let mut params = HashMap::new();
+                    params.insert("reminder_id".to_string(), reminder_id.clone());
+                    ("reminder.already_complete".to_string(), Some(params))
+                }
                 _ => ("command.invalid_format".to_string(), None),
             },
             ModmailError::Thread(thread_err) => match thread_err {
diff --git a/crates/rustmail/src/errors/types.rs b/crates/rustmail/src/errors/types.rs
index 43ce0095..6bf721ba 100644
--- a/crates/rustmail/src/errors/types.rs
+++ b/crates/rustmail/src/errors/types.rs
@@ -75,6 +75,7 @@ pub enum CommandError {
     ReminderAlreadyUnsubscribed(String),
     ReminderRoleRequired(String),
     ReminderRoleNotFound(String),
+    ReminderAlreadyCompleted(String),
 }
 
 #[derive(Debug, Clone)]
@@ -206,6 +207,9 @@ impl fmt::Display for CommandError {
             CommandError::ReminderRoleNotFound(role) => {
                 write!(f, "Role {} not found", role)
             }
+            CommandError::ReminderAlreadyCompleted(reminder_id) => {
+                write!(f, "Reminder {} has already been completed", reminder_id)
+            }
         }
     }
 }
diff --git a/crates/rustmail/src/i18n/language/en.rs b/crates/rustmail/src/i18n/language/en.rs
index d6edf64e..82a4a3a7 100644
--- a/crates/rustmail/src/i18n/language/en.rs
+++ b/crates/rustmail/src/i18n/language/en.rs
@@ -786,6 +786,10 @@ pub fn load_english_messages(dict: &mut ErrorDictionary) {
             "⏰ Reminder for {roles} scheduled for **{time}** ({remaining_time})\n\n{content}",
         ),
     );
+    dict.messages.insert(
+        "reminder.already_complete".to_string(),
+        DictionaryMessage::new("The reminder '#{reminder_id}' has already been completed."),
+    );
     dict.messages.insert(
         "reminder.show_with_content".to_string(),
         DictionaryMessage::new("⏰ Reminder <@{user}>: \n\n{content} !"),
diff --git a/crates/rustmail/src/i18n/language/fr.rs b/crates/rustmail/src/i18n/language/fr.rs
index ab2b52d5..ccd6d9f0 100644
--- a/crates/rustmail/src/i18n/language/fr.rs
+++ b/crates/rustmail/src/i18n/language/fr.rs
@@ -822,6 +822,10 @@ pub fn load_french_messages(dict: &mut ErrorDictionary) {
         "reminder.show_without_content_roles".to_string(),
         DictionaryMessage::new("⏰ Rappel pour {roles} !"),
     );
+    dict.messages.insert(
+        "reminder.already_complete".to_string(),
+        DictionaryMessage::new("Le rappel **#{reminder_id}** a déjà été complété."),
+    );
     dict.messages.insert(
         "slash_command.add_reminder_command_description".to_string(),
         DictionaryMessage::new("Ajouter un rappel pour vous-même"),