The Kanade-Lucas-Tomasi tracking (KLT) algorithm is widely used for local tracking of features. As it employs a translation model to find the feature tracks, KLT is not robust in the presence of distortions around the feature resulting in high inaccuracies in the tracks. In this paper we show that the window size in KLT must vary to adapt to the presence of distortions around each feature point in order to increase the number of useful tracks and minimize noisy ones. We propose an adaptive window size strategy for KLT that uses the KLT iterations as an indicator of the quality of the tracks to determine near-optimal window sizes, thereby significantly improving its robustness to distortions. Our evaluations with a well-known tracking dataset show that the proposed adaptive strategy outperforms the conventional fixed-window KLT in terms of robustness. In addition, compared to the well-known affine KLT, our method achieves comparable robustness at an average runtime speedup of 7x.