diff --git a/CHANGELOG.md b/CHANGELOG.md
index 5714c0d8..c34eb4ab 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -11,6 +11,7 @@ If you are upgrading from v0.16.x, replace the binary (or run `docker pull`). If
 ## Changed
 
 ## Fixed
+- Directory: Invalidate caches when group memberships change on an external directory.
 - Log viewer: All events show as `INFO`.
 
 ## [0.16.2] - 2026-04-28
diff --git a/crates/common/src/auth/access_token.rs b/crates/common/src/auth/access_token.rs
index ccd7081e..8adbfe1a 100644
--- a/crates/common/src/auth/access_token.rs
+++ b/crates/common/src/auth/access_token.rs
@@ -840,6 +840,9 @@ fn hash_account(account: &Account) -> u64 {
                 credential.expires_at.hash(&mut s);
                 hash_credential_permissions(&mut s, &credential.permissions);
             }
+            for group_id in account.member_group_ids.iter() {
+                group_id.hash(&mut s);
+            }
         }
         Account::Group(account) => {
             account.member_tenant_id.hash(&mut s);
diff --git a/crates/common/src/cache/directory.rs b/crates/common/src/cache/directory.rs
index 1462698d..0c68498e 100644
--- a/crates/common/src/cache/directory.rs
+++ b/crates/common/src/cache/directory.rs
@@ -4,7 +4,9 @@
  * SPDX-License-Identifier: AGPL-3.0-only OR LicenseRef-SEL
  */
 
-use crate::{Server, auth::DomainCache, ipc::BroadcastEvent};
+use crate::{
+    Server, auth::DomainCache, cache::invalidate::CacheInvalidationBuilder, ipc::BroadcastEvent,
+};
 use registry::{
     schema::{
         prelude::{Object, ObjectType},
@@ -126,10 +128,18 @@ impl Server {
                         .await
                         .caused_by(trc::location!())?
                     {
-                        RegistryWriteResult::Success(id) => Ok(AccountWithId {
-                            id: id.document_id(),
-                            account: updated_account.into(),
-                        }),
+                        RegistryWriteResult::Success(id) => {
+                            let mut invalidator = CacheInvalidationBuilder::default();
+                            invalidator.process_update(id, &current_account, &updated_account);
+                            self.invalidate_caches(invalidator)
+                                .await
+                                .caused_by(trc::location!())?;
+
+                            Ok(AccountWithId {
+                                id: id.document_id(),
+                                account: updated_account.into(),
+                            })
+                        }
                         failure => Err(trc::AuthEvent::Error
                             .into_err()
                             .caused_by(trc::location!())
@@ -287,17 +297,26 @@ impl Server {
                 }
 
                 if has_changes {
+                    let updated_account = Object::from(Account::Group(updated_account));
                     match self
                         .registry()
                         .write(RegistryWrite::update(
                             Id::from(account_id),
-                            &Object::from(Account::Group(updated_account)),
+                            &updated_account,
                             &current_account,
                         ))
                         .await
                         .caused_by(trc::location!())?
                     {
-                        RegistryWriteResult::Success(id) => Ok(id.document_id()),
+                        RegistryWriteResult::Success(id) => {
+                            let mut invalidator = CacheInvalidationBuilder::default();
+                            invalidator.process_update(id, &current_account, &updated_account);
+                            self.invalidate_caches(invalidator)
+                                .await
+                                .caused_by(trc::location!())?;
+
+                            Ok(id.document_id())
+                        }
                         failure => Err(trc::AuthEvent::Error
                             .into_err()
                             .caused_by(trc::location!())