diff --git a/profiles/src/apub/actions/apub/note.rs b/profiles/src/apub/actions/apub/note.rs
index 0543593..4596534 100644
--- a/profiles/src/apub/actions/apub/note.rs
+++ b/profiles/src/apub/actions/apub/note.rs
@@ -54,6 +54,7 @@ pub(super) fn note(
     }
 
     let published = note.published().req("published")?;
+    let updated = note.updated();
     let attributed_to = note
         .attributed_to()
         .req("attributed to")?
@@ -176,6 +177,7 @@ pub(super) fn note(
         title: title.to_owned(),
         description,
         published: Some(published.into()),
+        updated: updated.map(|u| u.into()),
         files: existing_files,
         visibility: find_visibility(note),
         local_only: false,
diff --git a/profiles/src/apub/actions/apub/person/mod.rs b/profiles/src/apub/actions/apub/person/mod.rs
index c758898..7b55999 100644
--- a/profiles/src/apub/actions/apub/person/mod.rs
+++ b/profiles/src/apub/actions/apub/person/mod.rs
@@ -97,6 +97,7 @@ pub(crate) fn person(
     let public_key = person.ext_one.public_key.public_key_pem.clone();
     let public_key_id = person.ext_one.public_key.id.clone();
     let published = person.published().req("published")?.into();
+    let updated = person.updated().map(|u| u.into());
 
     let login_required = person
         .to()
@@ -136,6 +137,7 @@ pub(crate) fn person(
             login_required: Some(login_required),
             icon,
             banner,
+            updated,
         })))
     } else {
         Ok(Ok(Box::new(CreateProfile {
@@ -153,6 +155,7 @@ pub(crate) fn person(
             icon,
             banner,
             published,
+            updated,
         })))
     }
 }
@@ -220,6 +223,7 @@ pub(crate) fn update_person(
         .map(|s| s.to_owned());
     let public_key_id = person.ext_one.public_key.id.clone();
     let public_key = person.ext_one.public_key.public_key_pem.clone();
+    let updated = person.updated().map(|u| u.into());
 
     let login_required = person
         .to()
@@ -252,6 +256,7 @@ pub(crate) fn update_person(
         login_required: Some(login_required),
         icon,
         banner,
+        updated,
     })))
 }
 
diff --git a/profiles/src/apub/actions/mod.rs b/profiles/src/apub/actions/mod.rs
index 23e6138..c06b363 100644
--- a/profiles/src/apub/actions/mod.rs
+++ b/profiles/src/apub/actions/mod.rs
@@ -272,6 +272,7 @@ pub struct CreateSubmission {
     local_only: bool,
     logged_in_only: bool,
     sensitive: bool,
+    updated: Option<DateTime<Utc>>,
 }
 
 impl CreateSubmission {
@@ -287,6 +288,7 @@ impl CreateSubmission {
             local_only: false,
             logged_in_only: false,
             sensitive: false,
+            updated: None,
         }
     }
 }
@@ -470,6 +472,7 @@ pub struct CreateProfile {
     icon: Option<Uuid>,
     banner: Option<Uuid>,
     published: DateTime<Utc>,
+    updated: Option<DateTime<Utc>>,
 }
 
 impl CreateProfile {
@@ -485,6 +488,7 @@ impl CreateProfile {
             icon: None,
             banner: None,
             published: Utc::now(),
+            updated: None,
         }
     }
 }
@@ -504,6 +508,7 @@ pub struct UpdateProfile {
     login_required: Option<bool>,
     icon: Option<Uuid>,
     banner: Option<Uuid>,
+    updated: Option<DateTime<Utc>>,
 }
 
 impl UpdateProfile {
@@ -530,6 +535,7 @@ impl UpdateProfile {
             login_required: None,
             icon: None,
             banner: None,
+            updated: Some(Utc::now()),
         }
     }
 
@@ -544,6 +550,7 @@ impl UpdateProfile {
             login_required: None,
             icon: Some(icon),
             banner: None,
+            updated: Some(Utc::now()),
         }
     }
 
@@ -558,6 +565,7 @@ impl UpdateProfile {
             login_required: None,
             icon: None,
             banner: Some(banner),
+            updated: Some(Utc::now()),
         }
     }
 
@@ -572,6 +580,7 @@ impl UpdateProfile {
             login_required: Some(login_required),
             icon: None,
             banner: None,
+            updated: Some(Utc::now()),
         }
     }
 }
diff --git a/profiles/src/apub/actions/profile.rs b/profiles/src/apub/actions/profile.rs
index 80132d8..d425db7 100644
--- a/profiles/src/apub/actions/profile.rs
+++ b/profiles/src/apub/actions/profile.rs
@@ -30,6 +30,9 @@ impl Action for CreateProfile {
         if let Some(icon) = self.icon {
             changes.icon(icon);
         }
+        if let Some(updated) = self.updated {
+            changes.updated(updated);
+        }
 
         let profile = if changes.any_changes() {
             ctx.store.profiles.update(&changes)?
@@ -88,6 +91,9 @@ impl Action for UpdateProfile {
         if let Some(description_source) = &self.description_source {
             changes.description_source(description_source);
         }
+        if let Some(updated) = self.updated {
+            changes.updated(updated);
+        }
 
         let previous_banner = profile.banner();
         let previous_icon = profile.icon();
diff --git a/profiles/src/apub/actions/submission.rs b/profiles/src/apub/actions/submission.rs
index c5cc644..5c6b3d8 100644
--- a/profiles/src/apub/actions/submission.rs
+++ b/profiles/src/apub/actions/submission.rs
@@ -27,6 +27,9 @@ impl Action for CreateSubmission {
         if let Some(description) = &self.description {
             changes.description(&hyaenidae_content::html(description));
         }
+        if let Some(updated) = self.updated {
+            changes.updated(updated);
+        }
 
         for file in &self.files {
             changes.add_file(*file);
diff --git a/profiles/src/apub/results/profile.rs b/profiles/src/apub/results/profile.rs
index 0791116..3d44537 100644
--- a/profiles/src/apub/results/profile.rs
+++ b/profiles/src/apub/results/profile.rs
@@ -149,6 +149,9 @@ impl Outbound for ProfileCreated {
             let image = build_image(banner, ctx)?;
             person.set_image(image);
         }
+        if let Some(updated) = profile.updated() {
+            person.set_updated(updated.into());
+        }
         if !profile.login_required() {
             person.add_to(public());
         }
@@ -265,6 +268,9 @@ impl Outbound for ProfileUpdated {
             let image = build_image(banner, ctx)?;
             person.set_image(image);
         }
+        if let Some(updated) = profile.updated() {
+            person.set_updated(updated.into());
+        }
         if !profile.login_required() {
             person.add_to(public());
         }
diff --git a/profiles/src/store/profile.rs b/profiles/src/store/profile.rs
index e4cabb4..dfdf9f0 100644
--- a/profiles/src/store/profile.rs
+++ b/profiles/src/store/profile.rs
@@ -14,6 +14,7 @@ pub struct ProfileChanges {
     login_required: Option<bool>,
     icon: Option<Uuid>,
     banner: Option<Uuid>,
+    updated: Option<DateTime<Utc>>,
 }
 
 #[derive(Clone, Debug)]
@@ -35,6 +36,7 @@ pub struct Profile {
     icon: Option<Uuid>,
     banner: Option<Uuid>,
     published: DateTime<Utc>,
+    updated: Option<DateTime<Utc>>,
     login_required: bool,
     suspended: bool,
 }
@@ -73,9 +75,9 @@ struct StoredProfile {
     #[serde(skip_serializing_if = "Option::is_none")]
     banner: Option<Uuid>,
     published: DateTime<Utc>,
+    updated: Option<DateTime<Utc>>,
     login_required: bool,
     created_at: DateTime<Utc>,
-    updated_at: DateTime<Utc>,
     #[serde(skip_serializing_if = "Option::is_none")]
     suspended_at: Option<DateTime<Utc>>,
 }
@@ -116,12 +118,18 @@ impl ProfileChanges {
         self
     }
 
+    pub(crate) fn updated(&mut self, updated: DateTime<Utc>) -> &mut Self {
+        self.updated = Some(updated);
+        self
+    }
+
     pub(crate) fn any_changes(&self) -> bool {
         self.display_name.is_some()
             || self.description.is_some()
             || self.login_required.is_some()
             || self.icon.is_some()
             || self.banner.is_some()
+            || self.updated.is_some()
     }
 }
 
@@ -142,6 +150,7 @@ impl Profile {
             login_required: None,
             icon: None,
             banner: None,
+            updated: None,
         }
     }
 
@@ -196,6 +205,10 @@ impl Profile {
         self.published
     }
 
+    pub fn updated(&self) -> Option<DateTime<Utc>> {
+        self.updated
+    }
+
     pub fn login_required(&self) -> bool {
         self.login_required
     }
@@ -253,9 +266,9 @@ impl Store {
                 icon: None,
                 banner: None,
                 published,
+                updated: None,
                 login_required: true,
                 created_at: now,
-                updated_at: now,
                 suspended_at: None,
             };
             serde_json::to_writer(writer, &stored_profile)?;
@@ -365,6 +378,13 @@ impl Store {
 
         let mut stored_profile: StoredProfile = serde_json::from_slice(&stored_profile_ivec)?;
 
+        if let Some(updated) = profile_changes.updated {
+            let previously_updated = stored_profile.updated.unwrap_or(stored_profile.published);
+            if updated < previously_updated {
+                return Err(StoreError::Outdated);
+            }
+        }
+
         if let Some(login_required) = profile_changes.login_required {
             stored_profile.login_required = login_required;
         }
@@ -386,7 +406,9 @@ impl Store {
         if let Some(banner) = profile_changes.banner {
             stored_profile.banner = Some(banner);
         }
-        stored_profile.updated_at = Utc::now().into();
+        if let Some(updated) = profile_changes.updated {
+            stored_profile.updated = Some(updated);
+        }
 
         let stored_profile_vec = serde_json::to_vec(&stored_profile)?;
 
@@ -533,7 +555,7 @@ impl Store {
         stored_profile.description = None;
         stored_profile.display_name = None;
         stored_profile.suspended_at = Some(now);
-        stored_profile.updated_at = now;
+        stored_profile.updated = Some(now);
         let stored_profile_vec = serde_json::to_vec(&stored_profile)?;
 
         if self
@@ -616,6 +638,7 @@ impl From<StoredProfile> for Profile {
             icon: sp.icon,
             banner: sp.banner,
             published: sp.published,
+            updated: sp.updated,
             login_required: sp.login_required,
             suspended: sp.suspended_at.is_some(),
         }