Amplification of Brillouin scattering signal extends the measurement range and improves the signal-to-noise ratio of fiber-optic distributed Brillouin sensors. Here, we investigate the amplification effect of a 980-nm pump laser on Brillouin gain spectrum in an erbium-doped optical fiber. The Brillouin-scattered Stokes power increased exponentially with increasing pump power, exhibiting approximately 87% enhancement at 252 mW compared with the Stokes power obtained without the pump. This suggests that a more significant increase in the Stokes power is feasible with a higher-power 980-nm pump laser.