diff --git a/scripts/boxes b/scripts/boxes
index 61c0fe3..b4dc4b8 100755
--- a/scripts/boxes
+++ b/scripts/boxes
@@ -23,7 +23,7 @@ from pkg_resources import get_distribution
 try:
     import boxes
 except ImportError:
-    sys.path.append(os.path.dirname(os.path.realpath(__file__)) + '/..')
+    sys.path.append(os.path.join(os.path.dirname(os.path.realpath(__file__)), '..'))
     import boxes
 
 import boxes.generators