diff --git a/internal/user/events.go b/internal/user/events.go
index 71098d8c..296243be 100644
--- a/internal/user/events.go
+++ b/internal/user/events.go
@@ -257,7 +257,7 @@ func (user *User) handleUpdateAddressEvent(_ context.Context, event proton.Addre
 		})
 
 		return nil
-	}, user.apiAddrsLock)
+	}, user.apiAddrsLock, user.updateChLock)
 }
 
 func (user *User) handleDeleteAddressEvent(_ context.Context, event proton.AddressEvent) error {
diff --git a/internal/user/user.go b/internal/user/user.go
index 5fbdb54b..c2634f0a 100644
--- a/internal/user/user.go
+++ b/internal/user/user.go
@@ -546,7 +546,7 @@ func (user *User) Close() {
 	user.client.Close()
 
 	// Close the user's update channels.
-	safe.RLock(func() {
+	safe.Lock(func() {
 		for _, updateCh := range xslices.Unique(maps.Values(user.updateCh)) {
 			updateCh.CloseAndDiscardQueued()
 		}