A common argument is that ‘social mix’—or a high ratio of homeowners and private renters to social housing tenants within the same neighbourhood—reduces disadvantage by eroding homogeneous ‘bonded’ social networks amongst the latter. However, associations between network homogeneity and support in social housing have not been analysed using national survey data. This article examines age, ethnic and educational homogeneity/heterogeneity and informal support using the 2006 Australian General Social Survey. Counter to expectations, social housing tenants have more heterogeneous friendship groups by all measures, regardless of respondents’age, ethnicity or education. In addition, friendship heterogeneity is associated with more informal support in social housing, but less support in private housing. This raises concerns over the efficacy of ‘socially mixing’ already heterogeneous social housing communities and suggests that resistance to social mix is likely to stem from the attitudes of homeowners and private renters towards social tenants rather than the reverse.