Although regarded as a promising approach for indoor localization, WiFi fingerprint-based localization can lead to potential location privacy violations. In this work, we study the location privacy issues of WiFi fingerprint-based localization and propose a lightweight location privacy-preserving scheme that does not rely on any cryptographic primitive as the existing work does. In our scheme, a to-be-localized user sends the measured signal strength values and other k-1 dummy signal strength values to the service provider who accordingly replies with k locations. The service provider cannot distinguish the user's location from the other k-1 dummy locations. Compared with the existing work, the computational and communication overhead of the proposed scheme are much lower.