diff --git a/apps/api/internal/store/postgres/postgres.go b/apps/api/internal/store/postgres/postgres.go
index 8340a0de..c7ad50be 100644
--- a/apps/api/internal/store/postgres/postgres.go
+++ b/apps/api/internal/store/postgres/postgres.go
@@ -1220,7 +1220,10 @@ func normalizeWorkspaceSettings(current store.Workspace, input store.UpdateWorks
 		if workspaceSlug == "" {
 			return "", "", "", errors.New("workspace slug is required")
 		}
-		if isReservedWorkspaceSlug(workspaceSlug) {
+		// A workspace that already owns a reserved slug (the Access-provisioned
+		// default workspace) must stay editable: rejecting its unchanged slug
+		// would block every name and icon update from the settings form.
+		if workspaceSlug != current.Slug && isReservedWorkspaceSlug(workspaceSlug) {
 			return "", "", "", errors.New("workspace slug is reserved")
 		}
 	}
diff --git a/apps/api/internal/store/sqlite/mutations_test.go b/apps/api/internal/store/sqlite/mutations_test.go
index bdb1c109..4830ddfb 100644
--- a/apps/api/internal/store/sqlite/mutations_test.go
+++ b/apps/api/internal/store/sqlite/mutations_test.go
@@ -700,3 +700,42 @@ func TestMutationsReturnOutboxErrors(t *testing.T) {
 		t.Fatal("expected message delete outbox error")
 	}
 }
+
+func TestUpdateWorkspaceKeepsReservedSlugEditable(t *testing.T) {
+	t.Parallel()
+	ctx := context.Background()
+	st := newTestStore(t)
+	owner, err := st.EnsureBootstrap(ctx, "Owner", "owner-reserved-slug@example.com")
+	if err != nil {
+		t.Fatal(err)
+	}
+	workspace, err := st.EnsureDefaultWorkspaceMember(ctx, owner.ID)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if !isReservedWorkspaceSlug(workspace.Slug) {
+		t.Fatalf("expected the provisioned default workspace to own a reserved slug, got %q", workspace.Slug)
+	}
+	// The settings form always submits the current slug alongside the name.
+	name := "Renamed default"
+	sameSlug := workspace.Slug
+	updated, _, err := st.UpdateWorkspace(ctx, store.UpdateWorkspaceInput{WorkspaceID: workspace.ID, ActorUserID: owner.ID, Name: &name, Slug: &sameSlug})
+	if err != nil {
+		t.Fatalf("expected an unchanged reserved slug to stay editable: %v", err)
+	}
+	if updated.Name != name || updated.Slug != workspace.Slug {
+		t.Fatalf("unexpected workspace after rename: %#v", updated)
+	}
+	otherReserved := "guests"
+	if _, _, err := st.UpdateWorkspace(ctx, store.UpdateWorkspaceInput{WorkspaceID: workspace.ID, ActorUserID: owner.ID, Slug: &otherReserved}); err == nil {
+		t.Fatal("expected a move to another reserved slug to be rejected")
+	}
+	regular, err := st.CreateWorkspace(ctx, store.CreateWorkspaceInput{Name: "Regular", Slug: "regular"}, owner.ID)
+	if err != nil {
+		t.Fatal(err)
+	}
+	takeReserved := workspace.Slug
+	if _, _, err := st.UpdateWorkspace(ctx, store.UpdateWorkspaceInput{WorkspaceID: regular.ID, ActorUserID: owner.ID, Slug: &takeReserved}); err == nil {
+		t.Fatal("expected a regular workspace to be refused a reserved slug")
+	}
+}
diff --git a/apps/api/internal/store/sqlite/sqlite.go b/apps/api/internal/store/sqlite/sqlite.go
index ed2ba518..1c4cba72 100644
--- a/apps/api/internal/store/sqlite/sqlite.go
+++ b/apps/api/internal/store/sqlite/sqlite.go
@@ -1232,7 +1232,10 @@ func normalizeWorkspaceSettings(current store.Workspace, input store.UpdateWorks
 		if workspaceSlug == "" {
 			return "", "", "", errors.New("workspace slug is required")
 		}
-		if isReservedWorkspaceSlug(workspaceSlug) {
+		// A workspace that already owns a reserved slug (the Access-provisioned
+		// default workspace) must stay editable: rejecting its unchanged slug
+		// would block every name and icon update from the settings form.
+		if workspaceSlug != current.Slug && isReservedWorkspaceSlug(workspaceSlug) {
 			return "", "", "", errors.New("workspace slug is reserved")
 		}
 	}