Methods, systems, and devices for wireless communications are described. In some systems, a first user equipment (UE) may monitor and perform blind decoding for a sidelink transmission, such as a first part of sidelink control information (SCI), from a second UE over a configured search space. The first UE may receive signaling indicating an update to the search space via lower layer signaling, such as via a second part of SCI or a sidelink data channel, and may monitor for the sidelink transmission over the updated search space. The update to the search space may indicate a blocking of one or more monitoring occasions from the configured search space, an addition of one or more monitoring occasions to the configured search space, a reactivation of one or more previously blocked monitoring occasions, or a switching from a first search space to a second search space.