The composition and amount of interstellar dust within gamma-ray burst (GRB) host galaxies is of key importance when addressing selection eﬀects in the GRB redshift distribution, and when studying the properties of their host galaxies. As well as the implications for GRB research, probing the dust within the high-z hosts of GRBs also contributes to our understanding of the conditions of the interstellar medium and star-formation inthe distant Universe. Nevertheless, the physical properties of dust withinGRB host galaxies continues to be a highly contended issue. In this paper we explore the mean extinction properties of dust within the host galaxies of a sample of 17 GRBs with total host galaxy visual extinction AV < 1( AV = 0.4), covering a redshift range z = 0.7−3.1. We ﬁnd theaverage host extinction curve to have an u ltraviolet slope comparable to that of the LMC, but with little evidence of a 2175 Å dust extinction feature as observed along Milky Way and LMC sightlines. We cannot at present rule out the presence of a 2175 Å feature, and both the standard SMC and LMC extinction curves also provide good ﬁts to our data. However, we can reject an extinction curve that has a UV slope as ﬂat as the mean Milky Way extinction curve, whilst also having a 2175 Å feature as prominent as seen in the mean MilkyWay extinctioncurve. This is incontrast tothe clear detection of a 2175 Å bump and the ﬂatterextinction curves of some more heavily extinguished GRBs (AV > 1), which may be indicative of there being a dependence between dust abundance and the wavelength dependence of dust extinction, as has been previously speculated.