diff --git a/bob/utils.py b/bob/utils.py
index b6880e3..7ce4764 100644
--- a/bob/utils.py
+++ b/bob/utils.py
@@ -48,6 +48,7 @@ def archive_tree(dir, archive):
 
     abspath = os.path.abspath(dir)
     base_root = None
+    transposed_base = None
     is_top_level = False
 
     with tarfile.open(archive, 'w:gz') as tar:
@@ -61,13 +62,18 @@ def archive_tree(dir, archive):
             if not base_root:
                 base_root = root
 
-            transposed_base = root[len(base_root)+1:]
+            # No path at all for the top-level directory.
+            if not is_top_level:
+                transposed_base = root[len(base_root)+1:]
+            else:
+                transposed_base = ''
+
 
             for file in files:
 
                 standard_path = os.path.join(root, file)
 
-                if is_top_level:
+                if not transposed_base:
                     transposed_path = file
                 else:
                     transposed_path = os.path.join(transposed_base, file)
@@ -75,6 +81,7 @@ def archive_tree(dir, archive):
                 # Add the file to the archive, with the proper transposed path.
                 tar.add(standard_path, arcname=transposed_path)
 
+
             # Close out the top-level directory marker.
             is_top_level = False