diff --git a/module/applications/dialogs/downtime.mjs b/module/applications/dialogs/downtime.mjs
index 15add3ad..4922b4ed 100644
--- a/module/applications/dialogs/downtime.mjs
+++ b/module/applications/dialogs/downtime.mjs
@@ -113,13 +113,24 @@ export default class DhpDowntime extends HandlebarsApplicationMixin(ApplicationV
 
     deselectMove(event) {
         const button = event.target.closest('.activity-container');
-        const move = button.dataset.move;
-        this.moveData[button.dataset.category].moves[move].selected = this.moveData[button.dataset.category].moves[move]
-            .selected
-            ? this.moveData[button.dataset.category].moves[move].selected - 1
+        const { move, category } = button.dataset;
+        this.moveData[category].moves[move].selected = this.moveData[category].moves[move].selected
+            ? this.moveData[category].moves[move].selected - 1
             : 0;
 
         this.render();
+
+        // On macOS with a single-button mouse (e.g. a laptop trackpad),
+        // right-click is triggered with ctrl+click, which triggers both a
+        // `contextmenu` event and a regular click event. We need to stop
+        // event propagation to prevent the click event from triggering the
+        // `selectMove` function and undoing the change we just made.
+        event.stopPropagation();
+
+        // Having stopped propagation, we're no longer subject to Foundry's
+        // default `contextmenu` handler, so we also have to prevent the
+        // default behaviour to prevent a context menu from appearing.
+        event.preventDefault();
     }
 
     static async takeDowntime() {