diff --git a/internal/app/cmd/register.go b/internal/app/cmd/register.go
index 5e2f5d8a..a6a3d2cf 100644
--- a/internal/app/cmd/register.go
+++ b/internal/app/cmd/register.go
@@ -276,7 +276,7 @@ func registerNoInteractive(ctx context.Context, configFile string, regArgs *regi
 	}
 	if err := inputs.validate(); err != nil {
 		log.WithError(err).Errorf("Invalid input, please re-run act command.")
-		return nil
+		return err
 	}
 	if err := doRegister(ctx, cfg, inputs); err != nil {
 		return fmt.Errorf("Failed to register runner: %w", err)
diff --git a/internal/app/cmd/register_test.go b/internal/app/cmd/register_test.go
index a69775a8..1283db97 100644
--- a/internal/app/cmd/register_test.go
+++ b/internal/app/cmd/register_test.go
@@ -6,6 +6,8 @@ package cmd
 import (
 	"slices"
 	"testing"
+
+	"github.com/stretchr/testify/assert"
 )
 
 func TestCommaSplit(t *testing.T) {
@@ -29,3 +31,12 @@ func TestCommaSplit(t *testing.T) {
 		}
 	}
 }
+
+func TestRegisterNonInteractiveReturnsLabelValidationError(t *testing.T) {
+	err := registerNoInteractive(t.Context(), "", &registerArgs{
+		Labels:       "label:invalid",
+		Token:        "token",
+		InstanceAddr: "http://localhost:3000",
+	})
+	assert.Error(t, err, "unsupported schema: invalid")
+}