diff --git a/pkg/identityserver/email.go b/pkg/identityserver/email.go
index 9407a67554..d19b0b353e 100644
--- a/pkg/identityserver/email.go
+++ b/pkg/identityserver/email.go
@@ -105,7 +105,7 @@ func (is *IdentityServer) SendNotificationEmailToUsers(ctx context.Context, noti
 
 		// Skips over the possible `support` user.
 		// This user can only be created via the API endpoints defined in the tenant access service.
-		if receiver.Ids.IDString() == "support" {
+		if receiver.Ids.IDString() == ttnpb.SupportUserID {
 			continue
 		}
 
diff --git a/pkg/identityserver/notification_registry.go b/pkg/identityserver/notification_registry.go
index 6eb9f0b2c2..83db4aa81f 100644
--- a/pkg/identityserver/notification_registry.go
+++ b/pkg/identityserver/notification_registry.go
@@ -347,7 +347,7 @@ func (is *IdentityServer) notifyAdminsInternal(ctx context.Context, req *ttnpb.C
 	for i, receiver := range receivers {
 		// Skips over the possible `support` user.
 		// This user can only be created via the API endpoints defined in the tenant access service.
-		if receiver.Ids.IDString() == "support" {
+		if receiver.Ids.IDString() == ttnpb.SupportUserID {
 			continue
 		}
 		receiverUserIDs[i] = receiver.Ids