diff --git a/doc/changelog.txt b/doc/changelog.txt
index 3d873b0..0e9ac32 100644
--- a/doc/changelog.txt
+++ b/doc/changelog.txt
@@ -10,6 +10,7 @@
 * Generate standalone Windows .exe and Linux .rpm installer.
 * Initialize the internal MIME database correct on all platforms.
 * Improved option compatibility for the ar, cpio and tar programs.
+* Require and use Python >=2.5
 
 
 0.16 "Game of thrones" (released 12.5.2012)
diff --git a/doc/install.txt b/doc/install.txt
index 2218a1f..cdfeab0 100644
--- a/doc/install.txt
+++ b/doc/install.txt
@@ -3,7 +3,7 @@ Installation
 
 First, install the required software.
 
-1. Python >= 2.4 from http://www.python.org/
+1. Python >= 2.5 from http://www.python.org/
    
    Be sure to also have installed the included distutils module.
    On most distributions, the distutils module is included in
diff --git a/patool b/patool
index 02d1f59..8120267 100755
--- a/patool
+++ b/patool
@@ -17,9 +17,6 @@
 """
 patool [extract|list|create|formats] [sub-command-options] <command-args>
 """
-import sys
-if not hasattr(sys, "version_info") or sys.version_info < (2, 4, 0, "final", 0):
-    raise SystemExit("This program requires Python 2.4 or later.")
 import os
 from patoolib import handle_archive, list_formats, baker
 
diff --git a/patoolib/__init__.py b/patoolib/__init__.py
index ad3d608..906c5f6 100644
--- a/patoolib/__init__.py
+++ b/patoolib/__init__.py
@@ -13,10 +13,13 @@
 #
 # You should have received a copy of the GNU General Public License
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
+import sys
+if not hasattr(sys, "version_info") or sys.version_info < (2, 5, 0, "final", 0):
+    raise SystemExit("This program requires Python 2.5 or later.")
 import os
 import shutil
 import stat
-from patoolib import util
+from . import util
 
 # Supported archive commands
 ArchiveCommands = ('list', 'extract', 'test', 'create')
@@ -507,7 +510,7 @@ def get_archive_cmdlist_func (program, command, format):
     module = ProgramModules.get(key, key)
     # import archive handler function (eg. patoolib.programs.star.extract_tar)
     args = (module, command, format)
-    import_cmd = "from patoolib.programs.%s import %s_%s as func" % args
+    import_cmd = "from .programs.%s import %s_%s as func" % args
     try:
         exec import_cmd
     except ImportError:
diff --git a/patoolib/programs/__init__.py b/patoolib/programs/__init__.py
index b497d4d..96f004f 100644
--- a/patoolib/programs/__init__.py
+++ b/patoolib/programs/__init__.py
@@ -13,7 +13,7 @@
 #
 # You should have received a copy of the GNU General Public License
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
-from patoolib import util
+from .. import util
 
 def extract_singlefile_standard (archive, compression, cmd, **kwargs):
     """Standard routine to extract a singlefile archive (like gzip)."""
diff --git a/patoolib/programs/bzip2.py b/patoolib/programs/bzip2.py
index b8ec5ef..7ae8a32 100644
--- a/patoolib/programs/bzip2.py
+++ b/patoolib/programs/bzip2.py
@@ -14,9 +14,8 @@
 # You should have received a copy of the GNU General Public License
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 """Archive commands for the bzip2 program."""
-from patoolib import util
-from patoolib.programs import extract_singlefile_standard, \
-    test_singlefile_standard
+from .. import util
+from . import extract_singlefile_standard, test_singlefile_standard
 
 extract_bzip2 = extract_singlefile_standard
 test_bzip2 = test_singlefile_standard
diff --git a/patoolib/programs/clzip.py b/patoolib/programs/clzip.py
index 554746f..a01fd5b 100644
--- a/patoolib/programs/clzip.py
+++ b/patoolib/programs/clzip.py
@@ -14,7 +14,7 @@
 # You should have received a copy of the GNU General Public License
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 """Archive commands for the clzip program."""
-from patoolib.programs import extract_singlefile_standard, \
+from . import extract_singlefile_standard, \
     test_singlefile_standard, create_singlefile_standard
 
 
diff --git a/patoolib/programs/compress.py b/patoolib/programs/compress.py
index 7ea0d6f..f03abb8 100644
--- a/patoolib/programs/compress.py
+++ b/patoolib/programs/compress.py
@@ -14,7 +14,7 @@
 # You should have received a copy of the GNU General Public License
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 """Archive commands for the uncompress.real program."""
-from patoolib import util
+from .. import util
 
 
 def create_compress (archive, compression, cmd, *args, **kwargs):
diff --git a/patoolib/programs/cpio.py b/patoolib/programs/cpio.py
index 382feef..84ece33 100644
--- a/patoolib/programs/cpio.py
+++ b/patoolib/programs/cpio.py
@@ -16,7 +16,7 @@
 """Archive commands for the cpio program."""
 import os
 import sys
-from patoolib import util
+from .. import util
 
 def extract_cpio (archive, compression, cmd, **kwargs):
     """Extract a CPIO archive."""
diff --git a/patoolib/programs/flac.py b/patoolib/programs/flac.py
index fb08802..a7646f5 100644
--- a/patoolib/programs/flac.py
+++ b/patoolib/programs/flac.py
@@ -14,7 +14,7 @@
 # You should have received a copy of the GNU General Public License
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 """Archive commands for the flac program."""
-from patoolib import util
+from .. import util
 
 def extract_flac (archive, compression, cmd, **kwargs):
     """Decompress a FLAC archive to a WAV file."""
diff --git a/patoolib/programs/gzip.py b/patoolib/programs/gzip.py
index af910bf..cdf3306 100644
--- a/patoolib/programs/gzip.py
+++ b/patoolib/programs/gzip.py
@@ -14,7 +14,7 @@
 # You should have received a copy of the GNU General Public License
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 """Archive commands for the gzip program."""
-from patoolib.programs import extract_singlefile_standard, \
+from . import extract_singlefile_standard, \
     test_singlefile_standard, create_singlefile_standard
 
 extract_gzip = extract_compress = extract_singlefile_standard
diff --git a/patoolib/programs/lbzip2.py b/patoolib/programs/lbzip2.py
index f1f3fd1..0a8f5e8 100644
--- a/patoolib/programs/lbzip2.py
+++ b/patoolib/programs/lbzip2.py
@@ -15,4 +15,4 @@
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 """Archive commands for the pbzip2 program."""
 # bzip2 and lbzip2 are compatible
-from patoolib.programs.bzip2 import extract_bzip2, test_bzip2, create_bzip2
+from .bzip2 import extract_bzip2, test_bzip2, create_bzip2
diff --git a/patoolib/programs/lrzip.py b/patoolib/programs/lrzip.py
index ba0cea4..586e172 100644
--- a/patoolib/programs/lrzip.py
+++ b/patoolib/programs/lrzip.py
@@ -15,7 +15,7 @@
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 """Archive commands for the lrzip program."""
 import os
-from patoolib import util
+from .. import util
 
 def extract_lrzip (archive, compression, cmd, **kwargs):
     """Extract a LRZIP archive."""
diff --git a/patoolib/programs/lzip.py b/patoolib/programs/lzip.py
index 28fec36..2d08d48 100644
--- a/patoolib/programs/lzip.py
+++ b/patoolib/programs/lzip.py
@@ -14,7 +14,7 @@
 # You should have received a copy of the GNU General Public License
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 """Archive commands for the lzip program."""
-from patoolib.programs import extract_singlefile_standard, \
+from . import extract_singlefile_standard, \
     test_singlefile_standard, create_singlefile_standard
 
 
diff --git a/patoolib/programs/lzma.py b/patoolib/programs/lzma.py
index fc4f008..1d39dec 100644
--- a/patoolib/programs/lzma.py
+++ b/patoolib/programs/lzma.py
@@ -14,7 +14,7 @@
 # You should have received a copy of the GNU General Public License
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 """Archive commands for the lzma program."""
-from patoolib.programs import extract_singlefile_standard, \
+from . import extract_singlefile_standard, \
     test_singlefile_standard, create_singlefile_standard
 
 
diff --git a/patoolib/programs/lzop.py b/patoolib/programs/lzop.py
index ea16ebb..8018541 100644
--- a/patoolib/programs/lzop.py
+++ b/patoolib/programs/lzop.py
@@ -14,7 +14,7 @@
 # You should have received a copy of the GNU General Public License
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 """Archive commands for the lzop program."""
-from patoolib.programs import extract_singlefile_standard
+from . import extract_singlefile_standard
 
 
 extract_lzop = extract_singlefile_standard
diff --git a/patoolib/programs/mac.py b/patoolib/programs/mac.py
index fe037b4..608b526 100644
--- a/patoolib/programs/mac.py
+++ b/patoolib/programs/mac.py
@@ -14,7 +14,7 @@
 # You should have received a copy of the GNU General Public License
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 """Archive commands for the MAC.exe program."""
-from patoolib import util
+from .. import util
 
 def extract_ape (archive, compression, cmd, **kwargs):
     """Decompress an APE archive to a WAV file."""
diff --git a/patoolib/programs/pbzip2.py b/patoolib/programs/pbzip2.py
index 876f95d..43cf57e 100644
--- a/patoolib/programs/pbzip2.py
+++ b/patoolib/programs/pbzip2.py
@@ -15,4 +15,4 @@
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 """Archive commands for the pbzip2 program."""
 # bzip2 and pbzip2 are compatible
-from patoolib.programs.bzip2 import extract_bzip2, test_bzip2, create_bzip2
+from .bzip2 import extract_bzip2, test_bzip2, create_bzip2
diff --git a/patoolib/programs/pdlzip.py b/patoolib/programs/pdlzip.py
index 554746f..a01fd5b 100644
--- a/patoolib/programs/pdlzip.py
+++ b/patoolib/programs/pdlzip.py
@@ -14,7 +14,7 @@
 # You should have received a copy of the GNU General Public License
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 """Archive commands for the clzip program."""
-from patoolib.programs import extract_singlefile_standard, \
+from . import extract_singlefile_standard, \
     test_singlefile_standard, create_singlefile_standard
 
 
diff --git a/patoolib/programs/pigz.py b/patoolib/programs/pigz.py
index 9e66532..98cc75d 100644
--- a/patoolib/programs/pigz.py
+++ b/patoolib/programs/pigz.py
@@ -14,4 +14,4 @@
 # You should have received a copy of the GNU General Public License
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 """Archive commands for the pigz program."""
-from patoolib.programs.gzip import extract_gzip, test_gzip, create_gzip, list_gzip
+from .gzip import extract_gzip, test_gzip, create_gzip, list_gzip
diff --git a/patoolib/programs/plzip.py b/patoolib/programs/plzip.py
index 47f60d0..99e1f9b 100644
--- a/patoolib/programs/plzip.py
+++ b/patoolib/programs/plzip.py
@@ -14,7 +14,7 @@
 # You should have received a copy of the GNU General Public License
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 """Archive commands for the plzip program."""
-from patoolib.programs import extract_singlefile_standard, \
+from . import extract_singlefile_standard, \
     test_singlefile_standard, create_singlefile_standard
 
 
diff --git a/patoolib/programs/py_bz2.py b/patoolib/programs/py_bz2.py
index 606b75c..e84796d 100644
--- a/patoolib/programs/py_bz2.py
+++ b/patoolib/programs/py_bz2.py
@@ -14,7 +14,7 @@
 # You should have received a copy of the GNU General Public License
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 """Archive commands for the bz2 Python module."""
-from patoolib import util
+from .. import util
 try:
     # try external bz2file module with multi-stream support
     import bz2file as bz2
diff --git a/patoolib/programs/py_echo.py b/patoolib/programs/py_echo.py
index 7b73f8e..e5d0ed7 100644
--- a/patoolib/programs/py_echo.py
+++ b/patoolib/programs/py_echo.py
@@ -15,7 +15,7 @@
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 """Archive commands echoing data, implemented by the Python print
 statement."""
-from patoolib import util
+from .. import util
 
 
 def list_bzip2 (archive, compression, cmd, **kwargs):
diff --git a/patoolib/programs/py_gzip.py b/patoolib/programs/py_gzip.py
index 6b60e1b..debae30 100644
--- a/patoolib/programs/py_gzip.py
+++ b/patoolib/programs/py_gzip.py
@@ -17,7 +17,7 @@
 from __future__ import absolute_import
 # now gzip refers to the Python standard module, not the local one
 import gzip
-from patoolib import util
+from .. import util
 
 READ_SIZE_BYTES = 1024*1024
 
diff --git a/patoolib/programs/py_tarfile.py b/patoolib/programs/py_tarfile.py
index db6d9e1..e2b6e9b 100644
--- a/patoolib/programs/py_tarfile.py
+++ b/patoolib/programs/py_tarfile.py
@@ -14,7 +14,7 @@
 # You should have received a copy of the GNU General Public License
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 """Archive commands for the tarfile Python module."""
-from patoolib import util
+from .. import util
 import tarfile
 
 READ_SIZE_BYTES = 1024*1024
diff --git a/patoolib/programs/py_zipfile.py b/patoolib/programs/py_zipfile.py
index ec2862f..0b4f8d8 100644
--- a/patoolib/programs/py_zipfile.py
+++ b/patoolib/programs/py_zipfile.py
@@ -14,7 +14,7 @@
 # You should have received a copy of the GNU General Public License
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 """Archive commands for the zipfile Python module."""
-from patoolib import util
+from .. import util
 import zipfile
 import os
 
diff --git a/patoolib/programs/rpm2cpio.py b/patoolib/programs/rpm2cpio.py
index f31521a..61ddf6b 100644
--- a/patoolib/programs/rpm2cpio.py
+++ b/patoolib/programs/rpm2cpio.py
@@ -15,7 +15,7 @@
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 """Archive commands for the rpm2cpio program."""
 import os
-from patoolib import util
+from .. import util
 
 def extract_rpm (archive, compression, cmd, **kwargs):
     """Extract a RPM archive."""
diff --git a/patoolib/programs/rzip.py b/patoolib/programs/rzip.py
index d70ca5b..5f80a1a 100644
--- a/patoolib/programs/rzip.py
+++ b/patoolib/programs/rzip.py
@@ -15,7 +15,7 @@
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 """Archive commands for the lrzip program."""
 import os
-from patoolib import util
+from .. import util
 
 def extract_rzip (archive, compression, cmd, **kwargs):
     """Extract a RZIP archive."""
diff --git a/patoolib/programs/shar.py b/patoolib/programs/shar.py
index d341404..f8033c4 100644
--- a/patoolib/programs/shar.py
+++ b/patoolib/programs/shar.py
@@ -14,7 +14,7 @@
 # You should have received a copy of the GNU General Public License
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 """Archive commands for the shar program."""
-from patoolib import util
+from .. import util
 
 def create_shar (archive, compression, cmd, *args, **kwargs):
     """Create a SHAR archive."""
diff --git a/patoolib/programs/shorten.py b/patoolib/programs/shorten.py
index 6b27f1c..ebfa254 100644
--- a/patoolib/programs/shorten.py
+++ b/patoolib/programs/shorten.py
@@ -14,7 +14,7 @@
 # You should have received a copy of the GNU General Public License
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 """Archive commands for the shorten program."""
-from patoolib import util
+from .. import util
 
 def extract_shn (archive, compression, cmd, **kwargs):
     """Decompress a SHN archive to a WAV file."""
diff --git a/patoolib/programs/uncompress.py b/patoolib/programs/uncompress.py
index 210a542..0981c60 100644
--- a/patoolib/programs/uncompress.py
+++ b/patoolib/programs/uncompress.py
@@ -14,7 +14,7 @@
 # You should have received a copy of the GNU General Public License
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 """Archive commands for the uncompress.real program."""
-from patoolib import util
+from .. import util
 
 
 def extract_compress (archive, compression, cmd, **kwargs):
diff --git a/patoolib/programs/xdms.py b/patoolib/programs/xdms.py
index f3300ec..dfe659d 100644
--- a/patoolib/programs/xdms.py
+++ b/patoolib/programs/xdms.py
@@ -14,7 +14,7 @@
 # You should have received a copy of the GNU General Public License
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 """Archive commands for the xdms program."""
-from patoolib import util
+from .. import util
 
 
 def extract_dms (archive, compression, cmd, **kwargs):
diff --git a/patoolib/programs/xz.py b/patoolib/programs/xz.py
index f90fb14..5023de7 100644
--- a/patoolib/programs/xz.py
+++ b/patoolib/programs/xz.py
@@ -14,7 +14,7 @@
 # You should have received a copy of the GNU General Public License
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 """Archive commands for the xz program."""
-from patoolib.programs import extract_singlefile_standard, \
+from . import extract_singlefile_standard, \
     test_singlefile_standard, create_singlefile_standard
 
 
diff --git a/patoolib/util.py b/patoolib/util.py
index 0338db5..c6c64d1 100644
--- a/patoolib/util.py
+++ b/patoolib/util.py
@@ -169,7 +169,7 @@ def guess_mime_mimedb (filename):
     mime, encoding = None, None
     if mimedb is not None:
         mime, encoding = mimedb.guess_type(filename, strict=False)
-    from patoolib import ArchiveMimetypes, ArchiveCompressions
+    from . import ArchiveMimetypes, ArchiveCompressions
     if mime not in ArchiveMimetypes and encoding in ArchiveCompressions:
         # Files like 't.txt.gz' are recognized with encoding as format, and
         # an unsupported mime-type like 'text/plain'. Fix this.
@@ -209,7 +209,7 @@ def guess_mime_file_mime (file_prog, filename):
     except OSError:
         # ignore errors, as file(1) is only a fallback
         return mime, encoding
-    from patoolib import ArchiveMimetypes
+    from . import ArchiveMimetypes
     if mime in Mime2Encoding:
         # try to look inside compressed archives
         cmd = [file_prog, "--brief", "--mime", "--uncompress", filename]