Gérard Diffloth reconstructed Proto-Waic in a 1980 paper. His classification is as follows (Sidwell 2009). (Note: Individual languages are highlighted in italics.)
Other Waic languages in Shan State, eastern Myanmar are En and Siam (Hsem), which are referred to by Scott (1900) as En and Son. Hsiu (2015) classifies En, Son, and Tai Loi in Scott (1900) as Waic languages, citing the Waic phonological innovation from Proto-Palaungic *s- > h- instead of the Angkuic phonological innovation from Proto-Palaungic *s- > s-.
- Hammarström, Harald; Forkel, Robert; Haspelmath, Martin, eds. (2017). "Waic". Glottolog 3.0. Jena, Germany: Max Planck Institute for the Science of Human History.
- Shintani Tadahiko. 2016. The Siam (Hsem) language. Linguistic survey of Tay cultural area (LSTCA), 107. Tokyo: ILCAA.
- Shintani Tadahiko. 2016. The Va (En) language. Linguistic survey of Tay cultural area (LSTCA), 108. Tokyo: ILCAA.
- Scott, J. G. 1900. Gazetteer of Upper Burma and the Shan States. Superintendent, Government Printing, Rangoon.
- Hsiu, Andrew. 2015. The Angkuic languages: a preliminary survey. Paper presented ICAAL 6 (6th International Conference on Austroasiatic Linguistics), Siem Reap, Cambodia.
- Sidwell, Paul. 2009. Classifying the Austroasiatic languages: history and state of the art. LINCOM studies in Asian linguistics, 76. Munich: Lincom Europa.
- Shintani Tadahiko. 2016. The Va (En) language. Linguistic survey of Tay cultural area (LSTCA) no. 108. Tokyo: Research Institute for Languages and Cultures of Asia and Africa (ILCAA).
- SOAS Wa Dictionary Project and Internet Database for Minority Languages of Burma (Myanmar)