diff --git a/abalon/spark/sparkutils.py b/abalon/spark/sparkutils.py
index 476b351..2983819 100644
--- a/abalon/spark/sparkutils.py
+++ b/abalon/spark/sparkutils.py
@@ -131,11 +131,11 @@ def debug_print (message):
     files = []
     for f in fs.listStatus(hadoop.fs.Path(src_dir)):
         if f.isFile():
-            files.append(str(f.getPath()))
+            files.append(f.getPath())
     if not files:
         raise ValueError("Source directory {} is empty".format(src_dir))
     # determine order of files in which they will be written:
-    files.sort()
+    files.sort(key=lambda f: str(f))
 
     # dst_permission = hadoop.fs.permission.FsPermission.valueOf(permission)      # , permission='-rw-r-----'
     out_stream = fs.create(hadoop.fs.Path(dst_file), overwrite)
diff --git a/abalon/version.py b/abalon/version.py
index 1e42ba7..1896a19 100644
--- a/abalon/version.py
+++ b/abalon/version.py
@@ -12,4 +12,4 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-version = '1.4.0'
+version = '1.4.1'