1) Heat-curable adhesive composition comprising: from 20 to 85% of a polyether (A) comprising 2 hydrolysable alkoxysilane-type end groups, having a viscosity, measured at 23° C., ranging from 25 to 40 Pa·s and of formula (I): in which: R1 and R2 represent an alkyl radical having 1 to 4 carbon atoms; R3 represents a linear alkylene radical having 1 to 6 carbon atoms; R4 represents an alkylene radical having 1 to 4 carbon atoms; n is an integer such that the number-average molecular weight Mn of the polymer of formula (I) is between 20 kDa and 40 kDa; p is an integer equal to 0, 1 or 2; from 15 to 80% of a compatible tackifying resin (B); and from 0.01 to 3% of a curing catalyst (C). 2) Self-adhesive support coated with the cured adhesive composition.3) Use for the manufacture of self-adhesive labels and/or tapes.