diff --git a/app/models/communication/block.rb b/app/models/communication/block.rb
index 5a3d64f09..c519a2c0f 100644
--- a/app/models/communication/block.rb
+++ b/app/models/communication/block.rb
@@ -100,24 +100,21 @@ def language
     @language ||= about.language
   end
 
-  def duplicate
+  def duplicate(to: about, reset_position: true)
     block = self.dup
+    block.about = to
+    block.migration_identifier = nil
+    block.position = nil if reset_position
     block.save
     block
   end
 
   def paste(about)
-    block = self.dup
-    block.about = about
-    block.position = nil # Will be computed on save
-    block.save
-    block
+    duplicate(to: about)
   end
 
   def localize_for!(new_localization)
-    localized_block = self.dup
-    localized_block.about = new_localization
-    localized_block.save
+    duplicate(to: new_localization, reset_position: false)
   end
 
   def empty?
diff --git a/app/models/concerns/as_localization.rb b/app/models/concerns/as_localization.rb
index 44f0af926..cf57ee26c 100644
--- a/app/models/concerns/as_localization.rb
+++ b/app/models/concerns/as_localization.rb
@@ -47,6 +47,8 @@ def localize_in!(language)
     # Localized should not be published immediately
     l10n.published = false if respond_to?(:published)
 
+    l10n.migration_identifier = nil if respond_to?(:migration_identifier)
+
     localize_other_attachments(l10n)
 
     # Blocks need an about, so we save before localizing blocks
diff --git a/app/models/concerns/duplicable.rb b/app/models/concerns/duplicable.rb
index 8363cc605..1f9252750 100644
--- a/app/models/concerns/duplicable.rb
+++ b/app/models/concerns/duplicable.rb
@@ -15,7 +15,7 @@ def duplicate
   def duplicate_blocks(from, to)
     return unless from.respond_to?(:blocks)
     from.blocks.ordered.each do |block|
-      duplicate_block(to, block)
+      block.duplicate(to: to)
     end
   end
 
@@ -23,6 +23,7 @@ def duplicate_blocks(from, to)
 
   def duplicate_instance
     instance = self.dup
+    instance.migration_identifier = nil if instance.respond_to?(:migration_identifier)
     instance.position = nil if instance.respond_to?(:position)
     instance.save
     instance
@@ -39,17 +40,11 @@ def duplicate_localizations_for(instance)
       instance_l10n.about = instance
       # note: fragile. It only works because every duplicate objects currently has a "title" property.
       instance_l10n.title = I18n.t('copy_of', title: l10n.title)
+      instance_l10n.migration_identifier = nil if instance_l10n.respond_to?(:migration_identifier)
       instance_l10n.published = false if instance_l10n.respond_to?(:published)
       instance_l10n.published_at = nil if instance_l10n.respond_to?(:published_at)
       instance_l10n.save
       duplicate_blocks(l10n, instance_l10n)
     end
   end
-
-  def duplicate_block(instance, block)
-    duplicated_block = block.dup
-    duplicated_block.about = instance
-    duplicated_block.position = block.position
-    duplicated_block.save
-  end
 end