diff --git a/pkg/unpack/unpacker.go b/pkg/unpack/unpacker.go
index 136a128ea..6d6f79def 100644
--- a/pkg/unpack/unpacker.go
+++ b/pkg/unpack/unpacker.go
@@ -145,6 +145,9 @@ func NewUnpacker(ctx context.Context, cs content.Store, opts ...UnpackerOpt) (*U
 			return nil, err
 		}
 	}
+	if len(u.platforms) == 0 {
+		return nil, fmt.Errorf("no unpack platforms defined: %w", errdefs.ErrInvalidArgument)
+	}
 	return u, nil
 }