diff --git a/CHANGELOG.md b/CHANGELOG.md
index 17ff40a76..625f44a42 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -3,11 +3,13 @@
 - Improved upgrade script
 - OpenAPI reservation endpoint can be filtered by date
 - OpenAPI users endpoint now returns the ID of the InvoicingProfile
+- Fix a bug: wrong counting of minutes used when using a prepaid pack
 - Fix a bug: empty advanced accounting code is not defaulted to the general setting
 - Fix a bug: invalid style in accounting codes settings
 - Fix a bug: wrong namespace for task cart_operator
 - [TODO DEPLOY] `rails fablab:fix:cart_operator`
 - [TODO DEPLOY] `rails fablab:setup:build_accounting_lines`
+- [TODO DEPLOY] `rails fablab:fix:pack_minutes_used`
 
 ## v5.8.1 2023 March 03
 
diff --git a/app/frontend/src/javascript/components/dashboard/reservations/prepaid-packs-panel.tsx b/app/frontend/src/javascript/components/dashboard/reservations/prepaid-packs-panel.tsx
index c1a0c94ab..26fc55032 100644
--- a/app/frontend/src/javascript/components/dashboard/reservations/prepaid-packs-panel.tsx
+++ b/app/frontend/src/javascript/components/dashboard/reservations/prepaid-packs-panel.tsx
@@ -125,7 +125,7 @@ const PrepaidPacksPanel: React.FC<PrepaidPacksPanelProps> = ({ user, onError })
             <div className='prepaid-packs-list-item'>
               <p className='name'>{pack.prepaid_pack.priceable.name}</p>
               {FormatLib.date(pack.expires_at) && <p className="end">{FormatLib.date(pack.expires_at)}</p>}
-              <p className="countdown"><span>{pack.minutes_used / 60}H</span> / {pack.prepaid_pack.minutes / 60}H</p>
+              <p className="countdown"><span>{(pack.prepaid_pack.minutes - pack.minutes_used) / 60}H</span> / {pack.prepaid_pack.minutes / 60}H</p>
             </div>
           </div>
           { /* usage history is not saved for now
diff --git a/app/services/prepaid_pack_service.rb b/app/services/prepaid_pack_service.rb
index caa72c24e..b86ac918b 100644
--- a/app/services/prepaid_pack_service.rb
+++ b/app/services/prepaid_pack_service.rb
@@ -60,11 +60,10 @@ class PrepaidPackService
       packs = user_packs(user, reservation.reservable).order(minutes_used: :desc)
       packs.each do |pack|
         pack_available = pack.prepaid_pack.minutes - pack.minutes_used
-        remaining = pack_available - consumed
-        remaining = 0 if remaining.negative?
-        pack_consumed = pack.prepaid_pack.minutes - remaining
-        pack.update(minutes_used: pack_consumed)
+        remaining = consumed > pack_available ? 0 : pack_available - consumed
+        pack.update(minutes_used: pack.prepaid_pack.minutes - remaining)
 
+        pack_consumed = consumed > pack_available ? pack_available : consumed
         consumed -= pack_consumed
       end
     end
diff --git a/lib/tasks/fablab/fix.rake b/lib/tasks/fablab/fix.rake
index edfff75a5..b40c709ac 100644
--- a/lib/tasks/fablab/fix.rake
+++ b/lib/tasks/fablab/fix.rake
@@ -295,7 +295,7 @@ namespace :fablab do
       Rake::Task['fablab:chain:invoices_items'].invoke
     end
 
-    desc '[release 5.6] fix operator of self-bought carts'
+    desc '[release 5.8.2] fix operator of self-bought carts'
     task cart_operator: :environment do |_task, _args|
       Order.where.not(statistic_profile_id: nil).find_each do |order|
         order.update(operator_profile_id: order.user&.invoicing_profile&.id)
@@ -304,5 +304,48 @@ namespace :fablab do
         order.update(statistic_profile_id: order.operator_profile&.user&.statistic_profile&.id)
       end
     end
+
+    desc '[release 5.8.2] fix prepaid packs minutes_used'
+    task pack_minutes_used: :environment do |_task, _args|
+      StatisticProfilePrepaidPack.where('minutes_used < 0').find_each do |sppp|
+        previous_packs = sppp.statistic_profile.statistic_profile_prepaid_packs
+                             .includes(:prepaid_pack)
+                             .where(prepaid_packs: { priceable: sppp.prepaid_pack.priceable })
+                             .where("statistic_profile_prepaid_packs.created_at <= '#{sppp.created_at.utc.strftime('%Y-%m-%d %H:%M:%S.%6N')}'")
+                             .order('statistic_profile_prepaid_packs.created_at')
+        remaining = {}
+        previous_packs.each do |pack|
+          available_minutes = pack.prepaid_pack.minutes
+          reservations = Reservation.where(reservable: sppp.prepaid_pack.priceable)
+                                    .where(statistic_profile_id: sppp.statistic_profile_id)
+                                    .where("created_at > '#{pack.created_at.utc.strftime('%Y-%m-%d %H:%M:%S.%6N')}'")
+          reservations.each do |reservation|
+            next if available_minutes.zero?
+
+            # if the previous pack has not covered all the duration of this reservation, we substract the remaining minutes from the current pack
+            if remaining[reservation.id]
+              if remaining[reservation.id] > available_minutes
+                consumed = available_minutes
+                remaining[reservation.id] = remaining[reservation.id] - available_minutes
+              else
+                consumed = remaining[reservation.id]
+                remaining.except!(reservation.id)
+              end
+            else
+              # if there was no remaining from the previous pack, we substract the reservation duration from the current pack
+              reservation_minutes = reservation.slots.map { |slot| (slot.end_at.to_time - slot.start_at.to_time) / 60.0 }.reduce(:+) || 0
+              if reservation_minutes > available_minutes
+                consumed = available_minutes
+                remaining[reservation.id] = reservation_minutes - consumed
+              else
+                consumed = reservation_minutes
+              end
+            end
+            available_minutes -= consumed
+          end
+          pack.update(minutes_used: pack.prepaid_pack.minutes - available_minutes)
+        end
+      end
+    end
   end
 end
diff --git a/test/models/statistic_profile_prepaid_pack_test.rb b/test/models/statistic_profile_prepaid_pack_test.rb
index be1172ccc..e5725a3dc 100644
--- a/test/models/statistic_profile_prepaid_pack_test.rb
+++ b/test/models/statistic_profile_prepaid_pack_test.rb
@@ -3,7 +3,7 @@
 require 'test_helper'
 
 class StatisticProfilePrepaidPackTest < ActiveSupport::TestCase
-  test 'coupon have a expries date' do
+  test 'prepaid pack have a expries date' do
     prepaid_pack = PrepaidPack.first
     user = User.find_by(username: 'jdupond')
     p = StatisticProfilePrepaidPack.create!(prepaid_pack: prepaid_pack, statistic_profile: user.statistic_profile)
diff --git a/test/services/prepaid_pack_service_test.rb b/test/services/prepaid_pack_service_test.rb
index 44953b343..26265cb21 100644
--- a/test/services/prepaid_pack_service_test.rb
+++ b/test/services/prepaid_pack_service_test.rb
@@ -37,4 +37,40 @@ class PrepaidPackServiceTest < ActiveSupport::TestCase
     minutes_available = PrepaidPackService.minutes_available(@acamus, @machine)
     assert_equal minutes_available, 480
   end
+
+  test 'member has multiple active packs' do
+    availabilities_service = Availabilities::AvailabilitiesService.new(@acamus)
+
+    # user with current pack reserve 8 slots (on 10 available in the pack)
+    slots = availabilities_service.machines([@machine], @acamus, { start: Time.current, end: 10.days.from_now })
+    reservation = Reservation.create(
+      reservable_id: @machine.id,
+      reservable_type: Machine.name,
+      slots: [slots[0], slots[1], slots[2], slots[3], slots[4], slots[5], slots[6], slots[7]],
+      statistic_profile_id: @acamus.statistic_profile.id
+    )
+
+    PrepaidPackService.update_user_minutes(@acamus, reservation)
+    minutes_available = PrepaidPackService.minutes_available(@acamus, @machine)
+    assert_equal 120, minutes_available
+
+    # user buy a new pack
+    prepaid_pack = PrepaidPack.first
+    StatisticProfilePrepaidPack.create!(prepaid_pack: prepaid_pack, statistic_profile: @acamus.statistic_profile)
+
+    minutes_available = PrepaidPackService.minutes_available(@acamus, @machine)
+    assert_equal 720, minutes_available
+
+    # user books a new reservation of 4 slots
+    reservation = Reservation.create(
+      reservable_id: @machine.id,
+      reservable_type: Machine.name,
+      slots: [slots[8], slots[9], slots[10], slots[11]],
+      statistic_profile_id: @acamus.statistic_profile.id
+    )
+
+    PrepaidPackService.update_user_minutes(@acamus, reservation)
+    minutes_available = PrepaidPackService.minutes_available(@acamus, @machine)
+    assert_equal 480, minutes_available
+  end
 end