"Could not extract dependent variables from models" error in vuong test in R

I want to compare two linear non-nested models:

m_softgis<-lm(price~district1+district2+popularity+...)
m_size<-lm(price~district1+district2+size+...)

but I get this error:

> vuong(m_softgis, m_size)
Error in vuong(m_softgis, m_size) : 
  Could not extract dependent variables from models.

What should I do?