Two experiments explored how counterfactual mind-sets interact with implementation intentions and affect their flexibility. Participants engaged in a subtractive mind-set, an additive mind-set, or a control condition and were subsequently given either goal intentions or implementation intentions that facilitated cue detection (Experiment 1) or the goal-directed response (Experiment 2). Dependent variables were the number of targets specified in the intentions and the legitimate alternatives to the targets (flexibility measure). In Experiment 1, the implementation intention (versus goal intention) group were better at detecting specified cues, but worse on alternatives, regardless of mind-set. In Experiment 2, an interaction emerged. For both specified and alternative responses, the subtractive mind-set paired with an implementation intention versus goal intention performed better. This pattern was reversed for additive mind-set conditions. Hence, how counterfactual mind-sets affect the flexibility of planning is dependent on the particular mind-set used and the specific operations of plan.