diff --git a/periodictable/__init__.py b/periodictable/__init__.py
index 57f523e..bd33733 100644
--- a/periodictable/__init__.py
+++ b/periodictable/__init__.py
@@ -28,7 +28,7 @@
 __docformat__ = 'restructuredtext en'
 __all__ = ['elements', 'neutron_sld', 'xray_sld',
            'formula', 'mix_by_weight', 'mix_by_volume'] # and all elements
-__version__ = "1.5.1"
+__version__ = "1.5.2"
 
 from . import core
 from . import mass