The economic load dispatch problem is a non-convex and non-linear optimization problem due to the inclusion of practical features such as valve point effects, prohibited operating zones, ramp rate limits, and transmission losses. For solving the non-convex economic load dispatch problem, a social spider algorithm has been proposed recently. This paper proposes a modified version of the social spider algorithm and studies the application of this version for solving the non-convex economic load dispatch problem. The proposed modification significantly improves the performance of the social spider algorithm. Four benchmark test systems having 6 units, 40 units, 80 units, and 140 units are considered to demonstrate the efficacy of the proposed algorithm. The results obtained from the modified social spider algorithm surpass the results obtained by the original social spider algorithm and significantly compete with the best results presented in previous literature.