Memory reactivation induces plasticity, rendering reactivated memories susceptible to interference. The currentstudy examined whether the method and strength of reactivation modulates retroactive interference effects. Two days afterlearning AB word pairs, memory for these pairs was either not reactivated, moderately reactivated (presentation of A cues in anunrelated task), or strongly reactivated (restudy of AB pairs or cued recall of B targets). Immediately afterwards, participantseither learned AC word pairs, DE word pairs, or performed an unrelated distractor task. Cued recall of target words wastested two days later. Strong reactivation before learning new material protected memory from retroactive interference andintrusions, whereas moderate reactivation resulted in both. This finding suggests that strong reactivation enhances event-baseddistinctiveness, counteracting memory modification. Results are discussed in reference to the testing effect literature and thereconsolidation account, and implications for educational practice are outlined.