A monofilament made of glass-resin composite has improved properties in compression, in particular at high temperature, and comprises glass filaments embedded in a crosslinked resin. The glass transition temperature of the resin is equal to or greater than 190° C. The elongation at break of the monofilament, measured at 23° C., is equal to or greater than 4.0%. The initial tensile modulus of the monofilament, measured at 23° C., is greater than 35 GPa. The real part of the complex modulus of the monofilament, measured at 190° C. by the DMTA method, is greater than 30 GPa. Pneumatic or non-pneumatic tires are reinforced with such a composite monofilament.