diff --git a/lib/tasks/migrate_from_mantis.rake b/lib/tasks/migrate_from_mantis.rake
index 465ca9958..ffa84d4ea 100644
--- a/lib/tasks/migrate_from_mantis.rake
+++ b/lib/tasks/migrate_from_mantis.rake
@@ -503,10 +503,20 @@ task :migrate_from_mantis => :environment do
   # Make sure bugs can refer bugs in other projects
   Setting.cross_project_issue_relations = 1 if Setting.respond_to? 'cross_project_issue_relations'
 
-  # Turn off email notifications
-  Setting.notified_events = []
+  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 settings
+    Setting.notified_events = old_notified_events
+    Setting.password_min_length = old_password_min_length
+  end
 
-  MantisMigrate.establish_connection db_params
-  MantisMigrate.migrate
 end
 end
diff --git a/lib/tasks/migrate_from_trac.rake b/lib/tasks/migrate_from_trac.rake
index 923b0c620..db36dfe05 100644
--- a/lib/tasks/migrate_from_trac.rake
+++ b/lib/tasks/migrate_from_trac.rake
@@ -762,10 +762,19 @@ namespace :redmine do
     prompt('Target project identifier') {|identifier| TracMigrate.target_project_identifier identifier}
     puts
 
-    # Turn off email notifications
-    Setting.notified_events = []
-
-    TracMigrate.migrate
+    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 settings
+      Setting.notified_events = old_notified_events
+      Setting.password_min_length = old_password_min_length
+    end
   end
 end