diff --git a/lib/tasks/migrate_from_mantis.rake b/lib/tasks/migrate_from_mantis.rake
index ae8d3bb66..ffa84d4ea 100644
--- a/lib/tasks/migrate_from_mantis.rake
+++ b/lib/tasks/migrate_from_mantis.rake
@@ -504,15 +504,18 @@ task :migrate_from_mantis => :environment do
   Setting.cross_project_issue_relations = 1 if Setting.respond_to? 'cross_project_issue_relations'
 
   old_notified_events = Setting.notified_events
+  old_password_min_length = Setting.password_min_length
   begin
     # Turn off email notifications temporarily
     Setting.notified_events = []
+    Setting.password_min_length = 4
     # Run the migration
     MantisMigrate.establish_connection db_params
     MantisMigrate.migrate
   ensure
-    # Restore previous notification settings even if the migration fails
+    # Restore previous settings
     Setting.notified_events = old_notified_events
+    Setting.password_min_length = old_password_min_length
   end
 
 end
diff --git a/lib/tasks/migrate_from_trac.rake b/lib/tasks/migrate_from_trac.rake
index 605707182..ece967d65 100644
--- a/lib/tasks/migrate_from_trac.rake
+++ b/lib/tasks/migrate_from_trac.rake
@@ -767,14 +767,17 @@ namespace :redmine do
     puts
 
     old_notified_events = Setting.notified_events
+    old_password_min_length = Setting.password_min_length
     begin
       # Turn off email notifications temporarily
       Setting.notified_events = []
+      Setting.password_min_length = 4
       # Run the migration
       TracMigrate.migrate
     ensure
-      # Restore previous notification settings even if the migration fails
+      # Restore previous settings
       Setting.notified_events = old_notified_events
+      Setting.password_min_length = old_password_min_length
     end
   end
 end