diff --git a/CHANGELOG.md b/CHANGELOG.md
index 143d8e48d..b24f9a321 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -7,6 +7,7 @@
 - Increased the width of the input field for the prices of the events
 - Fix a bug: the notification sent to the project author when a collaborator has confirmed his participation is not sent
 - Fix a bug: the event themes are not kept when editing the event again
+- Fix a bug: the count of successfully updated events was not correct
 - Fix a security issue: updated underscore to 1.12.1 to fix [CVE-2021-23358](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-23358)
 - Fix a security issue: updated lodash to 4.17.21 to fix [CVE-2021-23337](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-23337)
 - Fix a security issue: updated url-parse to 1.5.1 to fix [CVE-2021-27515](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-27515)
diff --git a/app/controllers/api/events_controller.rb b/app/controllers/api/events_controller.rb
index 3c145cb0f..0c051743a 100644
--- a/app/controllers/api/events_controller.rb
+++ b/app/controllers/api/events_controller.rb
@@ -64,7 +64,9 @@ class API::EventsController < API::ApiController
   def update
     authorize Event
     res = EventService.update(@event, event_params.permit!, params[:edit_mode])
-    render json: { action: 'update', total: res.length, updated: res.select { |r| r[:status] }.length, details: res }, status: :ok, location: @event
+    render json: { action: 'update', total: res[:events].length, updated: res[:events].select { |r| r[:status] }.length, details: res },
+           status: :ok,
+           location: @event
   end
 
   def destroy
diff --git a/app/services/event_service.rb b/app/services/event_service.rb
index 91b617c6c..6747aca36 100644
--- a/app/services/event_service.rb
+++ b/app/services/event_service.rb
@@ -102,7 +102,10 @@ class EventService
     private
 
     def update_events(event, events, event_params)
-      results = []
+      results = {
+        events: [],
+        slots: []
+      }
       events.each do |e|
         next unless e.id != event.id
 
@@ -164,18 +167,18 @@ class EventService
           event_files_attributes: ef_attributes
         )
         begin
-          results.push status: !!e.update(e_params.permit!), event: e # rubocop:disable Style/DoubleNegation
+          results[:events].push status: !!e.update(e_params.permit!), event: e # rubocop:disable Style/DoubleNegation
         rescue StandardError => err
-          results.push status: false, event: e, error: err.try(:record).try(:class).try(:name), message: err.message
+          results[:events].push status: false, event: e, error: err.try(:record).try(:class).try(:name), message: err.message
         end
-        results.concat(update_slots(e.availability_id))
+        results[:slots].concat(update_slots(e.availability_id))
       end
       begin
-        results.push status: !!event.update(event_params), event: event # rubocop:disable Style/DoubleNegation
+        results[:events].push status: !!event.update(event_params), event: event # rubocop:disable Style/DoubleNegation
       rescue StandardError => err
-        results.push status: false, event: event, error: err.try(:record).try(:class).try(:name), message: err.message
+        results[:events].push status: false, event: event, error: err.try(:record).try(:class).try(:name), message: err.message
       end
-      results.concat(update_slots(event.availability_id))
+      results[:slots].concat(update_slots(event.availability_id))
       results
     end