diff --git a/app/controllers/workshop_invitation_controller.rb b/app/controllers/workshop_invitation_controller.rb
index 6b3369864..7f777b3d3 100644
--- a/app/controllers/workshop_invitation_controller.rb
+++ b/app/controllers/workshop_invitation_controller.rb
@@ -68,6 +68,8 @@ def reject
         MemberActivityRecorder.record(actor: @invitation.member, key: 'workshop_invitation.rejected',
                                       trackable: @invitation)
 
+        WaitingList.find_by(invitation_id: @invitation.id)&.destroy
+
         next_spot = WaitingList.next_spot(@invitation.workshop, @invitation.role)
 
         if next_spot.present?
diff --git a/spec/controllers/workshop_invitation_controller_spec.rb b/spec/controllers/workshop_invitation_controller_spec.rb
index 21fbc136d..5133b42d8 100644
--- a/spec/controllers/workshop_invitation_controller_spec.rb
+++ b/spec/controllers/workshop_invitation_controller_spec.rb
@@ -170,6 +170,37 @@
         expect(waitlisted_invitation.reload.attending).to be true
       end
     end
+
+    context 'when the rejecting member is on the waiting list' do
+      before do
+        invitation.update!(attending: true)
+        WaitingList.add(invitation, auto_rsvp: true)
+      end
+
+      it 'removes their own waiting-list entry' do
+        post :reject, params: { id: invitation.token }
+
+        expect(WaitingList.where(invitation:)).to be_empty
+      end
+
+      it 'does not redeliver the seat to the cancelling member' do
+        post :reject, params: { id: invitation.token }
+
+        expect(invitation.reload.attending).to be false
+      end
+
+      it 'promotes the next student on the waiting list instead' do
+        member_behind = Fabricate(:member)
+        invitation_behind = Fabricate(:workshop_invitation, workshop:, member: member_behind, role: 'Student')
+        WaitingList.add(invitation_behind, auto_rsvp: true)
+
+        post :reject, params: { id: invitation.token }
+
+        expect(invitation_behind.reload.attending).to be true
+        expect(invitation.reload.attending).to be false
+        expect(WaitingList.where(invitation:)).to be_empty
+      end
+    end
   end
 
   describe 'PATCH #update' do