diff --git a/pyexcel_pdfr/_version.py b/pyexcel_pdfr/_version.py
index 817e5a8..34ce970 100644
--- a/pyexcel_pdfr/_version.py
+++ b/pyexcel_pdfr/_version.py
@@ -1,2 +1,2 @@
-__version__ = "0.6.0"
-__author__ = "chfw"
+__version__ = '0.6.0'
+__author__ = 'chfw'