diff --git a/internal/homesick/core/core.go b/internal/homesick/core/core.go
index f3c3f36..6668437 100644
--- a/internal/homesick/core/core.go
+++ b/internal/homesick/core/core.go
@@ -28,6 +28,13 @@ type App struct {
 }
 
 func New(stdout io.Writer, stderr io.Writer) (*App, error) {
+	if stdout == nil {
+		return nil, errors.New("stdout writer cannot be nil")
+	}
+	if stderr == nil {
+		return nil, errors.New("stderr writer cannot be nil")
+	}
+
 	home, err := os.UserHomeDir()
 	if err != nil {
 		return nil, fmt.Errorf("resolve home directory: %w", err)