diff --git a/lib/tasks/migrate_from_mantis.rake b/lib/tasks/migrate_from_mantis.rake
index f0b65e2aa..465ca9958 100644
--- a/lib/tasks/migrate_from_mantis.rake
+++ b/lib/tasks/migrate_from_mantis.rake
@@ -18,7 +18,7 @@
 desc 'Mantis migration script'
 
 require 'active_record'
-require 'iconv'
+require 'iconv' if RUBY_VERSION < '1.9'
 require 'pp'
 
 namespace :redmine do
@@ -440,9 +440,7 @@ task :migrate_from_mantis => :environment do
     end
 
     def self.encoding(charset)
-      @ic = Iconv.new('UTF-8', charset)
-    rescue Iconv::InvalidEncoding
-      return false
+      @charset = charset
     end
 
     def self.establish_connection(params)
@@ -454,9 +452,12 @@ task :migrate_from_mantis => :environment do
     end
 
     def self.encode(text)
-      @ic.iconv text
-    rescue
-      text
+      if RUBY_VERSION < '1.9'
+        @ic ||= Iconv.new('UTF-8', @charset)
+        @ic.iconv text
+      else
+        text.to_s.force_encoding(@charset).encode('UTF-8')
+      end
     end
   end
 
diff --git a/lib/tasks/migrate_from_trac.rake b/lib/tasks/migrate_from_trac.rake
index f48d205a4..923b0c620 100644
--- a/lib/tasks/migrate_from_trac.rake
+++ b/lib/tasks/migrate_from_trac.rake
@@ -16,7 +16,7 @@
 # Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
 
 require 'active_record'
-require 'iconv'
+require 'iconv' if RUBY_VERSION < '1.9'
 require 'pp'
 
 namespace :redmine do
@@ -603,10 +603,7 @@ namespace :redmine do
       end
 
       def self.encoding(charset)
-        @ic = Iconv.new('UTF-8', charset)
-      rescue Iconv::InvalidEncoding
-        puts "Invalid encoding!"
-        return false
+        @charset = charset
       end
 
       def self.set_trac_directory(path)
@@ -713,11 +710,13 @@ namespace :redmine do
         end
       end
 
-    private
       def self.encode(text)
-        @ic.iconv text
-      rescue
-        text
+        if RUBY_VERSION < '1.9'
+          @ic ||= Iconv.new('UTF-8', @charset)
+          @ic.iconv text
+        else
+          text.to_s.force_encoding(@charset).encode('UTF-8')
+        end
       end
     end