Cycloaliphatic epoxy (CE) systems are resistant to many aging mechanisms, which make them useful in applications with harsh environments. Reinforcement has been used in epoxy systems to decrease water absorption and improve aging resistance; thus, it is expected that talc would benefit CE systems in a similar manner. Neat, 10, and 20 wt% talc/CE composites were aged at 50 °C and 100% relative humidity for up to 398 hr. Three‐point bend testing and dynamic mechanical analysis were performed on the aged and unaged samples. Talc reduced the amount of water absorbed in the composites significantly, and increased the composite flexural stiffness at all aging levels. Talc does not appear to mitigate the negative effects of aging on flexural strength or glass transition temperature (Tg). POLYM. COMPOS., 40:2946–2953, 2019. © 2018 Society of Plastics Engineers