Indirect time-of-flight (ToF) imaging systems enable a broad array of applications owing to their high frame rate, strong durability, and low cost. However, the wiggling-related error caused by the harmonics in the emitted signal significantly affects the range accuracy of indirect ToF imaging systems. In this paper, we establish a mathematical model of the wiggling-related error and propose a wiggling-related error correction method for indirect ToF imaging systems. This method adds a delay measurement and utilizes raw intensity measurements to evaluate the system state based on an adaptive Kalman filter (AKF), which is easy to implement in most indirect ToF imaging systems. Simulation and experimental results show that the proposed method performed well in reducing the wiggling-related error and had good robustness in different integration times. Compared with the existing methods, the proposed method not only has better performance but also is easier to implement. We believe that this study provides effective guidance for researchers understanding the wiggling-related error and a potential direction for the accuracy improvement of indirect ToF imaging systems.