diff --git a/app/services/footprint_service.rb b/app/services/footprint_service.rb
index c4d60b651..394280ee8 100644
--- a/app/services/footprint_service.rb
+++ b/app/services/footprint_service.rb
@@ -1,49 +1,62 @@
 # frozen_string_literal: true
 
+require 'checksum'
+
 # Provides helper methods to compute footprints
 class FootprintService
-  # Compute the footprint
-  # @param klass Invoice|InvoiceItem|HistoryValue
-  # @param item an instance of the provided class
-  # @param sort the items in database by the provided criterion, to find the previous one
-  def self.compute_footprint(klass, item, sort_on = 'id')
-    Checksum.text(FootprintService.footprint_data(klass, item, sort_on))
-  end
+  class << self
+    # Compute the footprint
+    # @param klass a class inheriting from Footprintable
+    # @param item an instance of the provided class
+    # @param sort_on the items in database by the provided criterion, to find the previous one
+    def compute_footprint(klass, item, sort_on = 'id')
+      Checksum.text(FootprintService.footprint_data(klass, item, sort_on))
+    end
 
-  # Return the original data string used to compute the footprint
-  # @param klass Invoice|InvoiceItem|HistoryValue
-  # @param item an instance of the provided class
-  # @param sort the items in database by the provided criterion, to find the previous one
-  def self.footprint_data(klass, item, sort_on = 'id')
-    raise TypeError unless item.is_a? klass
+    # Return the original data string used to compute the footprint
+    # @param klass a class inheriting from Footprintable
+    # @param item an instance of the provided class
+    # @param sort_on the items in database by the provided criterion, to find the previous one
+    def footprint_data(klass, item, sort_on = 'id')
+      raise TypeError unless item.is_a? klass
 
-    previous = klass.where("#{sort_on} < ?", item[sort_on])
-                 .order("#{sort_on} DESC")
-                 .limit(1)
+      previous = klass.where("#{sort_on} < ?", item[sort_on])
+                   .order("#{sort_on} DESC")
+                   .limit(1)
 
-    columns  = FootprintService.footprint_columns(klass)
+      columns  = FootprintService.footprint_columns(klass)
 
-    "#{columns.map { |c| item[c] }.join}#{previous.first ? previous.first.footprint : ''}"
-  end
+      "#{columns.map { |c| comparable(item[c]) }.join}#{previous.first ? previous.first.footprint : ''}"
+    end
 
-  # Return an ordered array of the columns used in the footprint computation
-  # @param klass Invoice|InvoiceItem|HistoryValue
-  def self.footprint_columns(klass)
-    klass.columns.map(&:name).delete_if { |c| %w[footprint updated_at].concat(klass.columns_out_of_footprint).include? c }
-  end
+    # Return an ordered array of the columns used in the footprint computation
+    # @param klass a class inheriting from Footprintable
+    def footprint_columns(klass)
+      klass.columns.map(&:name).delete_if { |c| %w[footprint updated_at].concat(klass.columns_out_of_footprint).include? c }
+    end
 
-  # Logs a debugging message to help finding why a footprint is invalid
-  # @param klass Invoice|InvoiceItem|HistoryValue
-  # @param item an instance of the provided class
-  def self.debug_footprint(klass, item)
-    columns = FootprintService.footprint_columns(klass)
-    current = FootprintService.footprint_data(klass, item)
-    saved = FootprintDebug.find_by(footprint: item.footprint, klass: klass.name)
-    puts "Debug footprint for #{klass} [ id: #{item.id} ]"
-    puts '-----------------------------------------'
-    puts "columns: [ #{columns.join(', ')} ]"
-    puts "current footprint: #{current}"
-    puts "  saved footprint: #{saved&.data}"
-    puts '-----------------------------------------'
+    # Logs a debugging message to help finding why a footprint is invalid
+    # @param klass a class inheriting from Footprintable
+    # @param item an instance of the provided class
+    def debug_footprint(klass, item)
+      columns = FootprintService.footprint_columns(klass)
+      current = FootprintService.footprint_data(klass, item)
+      saved = FootprintDebug.find_by(footprint: item.footprint, klass: klass.name)
+      puts "Debug footprint for #{klass} [ id: #{item.id} ]"
+      puts '-----------------------------------------'
+      puts "columns: [ #{columns.join(', ')} ]"
+      puts "current: #{current}"
+      puts "  saved: #{saved&.data}"
+      puts '-----------------------------------------'
+    end
+
+    private
+
+    # Return a comparable value for jsonb fields (with keys ordered alphabetically)
+    def comparable(value)
+      return value unless value.class == Hash
+
+      value.sort.to_h
+    end
   end
 end
diff --git a/lib/tasks/fablab/maintenance.rake b/lib/tasks/fablab/maintenance.rake
index f9f8d0523..caa4b1dee 100644
--- a/lib/tasks/fablab/maintenance.rake
+++ b/lib/tasks/fablab/maintenance.rake
@@ -98,7 +98,7 @@ namespace :fablab do
 
     desc 'save the footprint original data'
     task save_footprint_data: :environment do
-      [Invoice, InvoiceItem, HistoryValue].each do |klass|
+      [Invoice, InvoiceItem, HistoryValue, PaymentSchedule, PaymentScheduleItem].each do |klass|
         klass.all.each do |item|
           FootprintDebug.create!(
             footprint: item.footprint,