diff --git a/lib/redmine/codeset_util.rb b/lib/redmine/codeset_util.rb
index b74a3a9e7..41ea85153 100644
--- a/lib/redmine/codeset_util.rb
+++ b/lib/redmine/codeset_util.rb
@@ -1,4 +1,6 @@
-require 'iconv'
+if RUBY_VERSION < '1.9'
+  require 'iconv'
+end
 
 module Redmine
   module CodesetUtil
@@ -100,10 +102,17 @@ module Redmine
       end
       encodings = Setting.repositories_encodings.split(',').collect(&:strip)
       encodings.each do |encoding|
-        begin
-          return Iconv.conv('UTF-8', encoding, str)
-        rescue Iconv::Failure
-          # do nothing here and try the next encoding
+        if str.respond_to?(:force_encoding)
+          str.force_encoding(encoding)
+          if str.valid_encoding?
+            return str.encode('UTF-8')
+          end
+        else
+          begin
+            return Iconv.conv('UTF-8', encoding, str)
+          rescue Iconv::Failure
+            # do nothing here and try the next encoding
+          end
         end
       end
       str = self.replace_invalid_utf8(str)
diff --git a/lib/redmine/export/pdf.rb b/lib/redmine/export/pdf.rb
index e650964eb..ff3993f72 100644
--- a/lib/redmine/export/pdf.rb
+++ b/lib/redmine/export/pdf.rb
@@ -17,12 +17,15 @@
 # along with this program; if not, write to the Free Software
 # Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
 
-require 'iconv'
 require 'tcpdf'
 require 'fpdf/chinese'
 require 'fpdf/japanese'
 require 'fpdf/korean'
 
+if RUBY_VERSION < '1.9'
+  require 'iconv'
+end
+
 module Redmine
   module Export
     module PDF
@@ -86,7 +89,7 @@ module Redmine
 
         def SetTitle(txt)
           txt = begin
-            utf16txt = Iconv.conv('UTF-16BE', 'UTF-8', txt)
+            utf16txt = to_utf16(txt)
             hextxt = "<FEFF"  # FEFF is BOM
             hextxt << utf16txt.unpack("C*").map {|x| sprintf("%02X",x) }.join
             hextxt << ">"
@@ -109,6 +112,15 @@ module Redmine
           RDMPdfEncoding::rdm_from_utf8(txt, l(:general_pdf_encoding))
         end
 
+        # Encodes an UTF-8 string to UTF-16BE
+        def to_utf16(str)
+          if str.respond_to?(:encode)
+            str.encode('UTF-16BE')
+          else
+            Iconv.conv('UTF-16BE', 'UTF-8', str)
+          end
+        end
+
         def RDMCell(w ,h=0, txt='', border=0, ln=0, align='', fill=0, link='')
           Cell(w, h, fix_text_encoding(txt), border, ln, align, fill, link)
         end
@@ -154,7 +166,7 @@ module Redmine
 
         def bookmark_title(txt)
           txt = begin
-            utf16txt = Iconv.conv('UTF-16BE', 'UTF-8', txt)
+            utf16txt = to_utf16(txt)
             hextxt = "<FEFF"  # FEFF is BOM
             hextxt << utf16txt.unpack("C*").map {|x| sprintf("%02X",x) }.join
             hextxt << ">"
diff --git a/lib/redmine/scm/adapters/abstract_adapter.rb b/lib/redmine/scm/adapters/abstract_adapter.rb
index 0f77d58d8..4458baa7e 100644
--- a/lib/redmine/scm/adapters/abstract_adapter.rb
+++ b/lib/redmine/scm/adapters/abstract_adapter.rb
@@ -17,6 +17,10 @@
 
 require 'cgi'
 
+if RUBY_VERSION < '1.9'
+  require 'iconv'
+end
+
 module Redmine
   module Scm
     module Adapters
diff --git a/test/unit/lib/redmine/export/pdf_test.rb b/test/unit/lib/redmine/export/pdf_test.rb
index 6046ab97c..7b9488de0 100644
--- a/test/unit/lib/redmine/export/pdf_test.rb
+++ b/test/unit/lib/redmine/export/pdf_test.rb
@@ -16,7 +16,6 @@
 # Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
 
 require File.expand_path('../../../../../test_helper', __FILE__)
-require 'iconv'
 
 class PdfTest < ActiveSupport::TestCase
   fixtures :users, :projects, :roles, :members, :member_roles,