diff --git a/gitosis/init.py b/gitosis/init.py
index 11075dc..6b0d7ad 100644
--- a/gitosis/init.py
+++ b/gitosis/init.py
@@ -11,6 +11,7 @@
 from cStringIO import StringIO
 from ConfigParser import RawConfigParser
 
+from stat import ST_MODE
 from gitosis import repository
 from gitosis import run_hook
 from gitosis import ssh
@@ -78,7 +79,9 @@ def init_admin_repository(
         path=git_dir,
         )
     hook = os.path.join(git_dir, 'hooks', 'post-update')
-    os.chmod(hook, 0755)
+    mode = os.stat(hook)[ST_MODE]
+    if not (mode & 0755) == 0755:
+        os.chmod(hook, 0755)
     if not repository.has_initial_commit(git_dir):
         log.info('Making initial commit...')
         # ConfigParser does not guarantee order, so jump through hoops
diff --git a/gitosis/repository.py b/gitosis/repository.py
index 6445e12..bf66324 100644
--- a/gitosis/repository.py
+++ b/gitosis/repository.py
@@ -5,6 +5,7 @@
 import subprocess
 import sys
 
+from stat import ST_MODE
 from pkg_resources import resource_filename
 from gitosis import util
 
@@ -42,7 +43,7 @@ def init(
         template = resource_filename('gitosis.templates', 'default')
 
 
-    util.mkdir(path, 0750)
+    util.mkdir(path, 0755)
     args = [
         _git,
         '--git-dir=.',
@@ -71,9 +72,11 @@ def init(
     if not os.path.exists(hooks_dir):
         raise
     for hook in hooks:
-        os.chmod(
-            os.path.join(hooks_dir, hook),
-            0755)
+        mode = os.stat(os.path.join(hooks_dir, hook))[ST_MODE]
+        if not (mode & 0755) == 0755:
+            os.chmod(
+                os.path.join(hooks_dir, hook),
+                0755)
 
 
 class GitFastImportError(GitError):
@@ -234,4 +237,4 @@ def mirror(git_dir, remote):
         close_fds=True
         )
     if returncode != 0:
-        raise GitPushMirrorException('exit status %d' % returncode)
\ No newline at end of file
+        raise GitPushMirrorException('exit status %d' % returncode)
diff --git a/gitosis/templates/default/hooks/post-receive b/gitosis/templates/default/hooks/post-receive
old mode 100644
new mode 100755