Single-error correction, double-error detection (SEC–DED) codes are a type of error-correction codes widely used in electronics to protect memory devices from data corruption. Odd-weight-column SEC–DED codes are a type of these codes where the parity-check matrix is built with every column including an odd number of ones. With this approach, double errors have an even-weight syndrome and can be differentiated from single errors and, consequently, easily detected. There are applications, such as avionics or space, where a multiple error usually affects adjacent cells. Adapting SEC–DED codes to protect against triple-adjacent errors is interesting in these applications. A modification to existing odd-weight-column SEC–DED codes to add triple-adjacent error detection (TAED), creating SEC–DED–TAED codes, is presented. The implementation of the additional triple-adjacent detection logic for these codes can be performed with limited performance and area overhead.