Scattered radiation is a major cause of image degradation in modern cone-beam computed tomography (CBCT) scanners, both in the medical field as well as in non-destructive testing. In this work, we present a novel method for scatter correction in CBCT based on temporal primary modulation. In contrast to primary modulation methods in the spatial domain reported in the literature, temporal modulation does not suffer inaccuracies in the scatter image caused by overlapping spectral copies. Additionally, it is shown that the maximum detectable frequency in the scatter function can be increased by a factor of two compared to spatial primary modulation methods. Moreover, the measuring time is not increased. We demonstrate first experimental results obtained with an industrial CBCT scanner employing our new scatter correction method.