diff --git a/owslib/wmts.py b/owslib/wmts.py
index 19717dc2..3b30780d 100644
--- a/owslib/wmts.py
+++ b/owslib/wmts.py
@@ -816,7 +816,7 @@ def __init__(self, elem, parent=None, index=0, parse_remote_metadata=False):
 
             values = [f.text for f in dim.findall(_DIMENSION_VALUE_TAG)]
             if len(values) == 0:
-                 raise ValueError(
+                raise ValueError(
                     '%s list of values can not be empty' % (dim,)
                 )
             dimension['values'] = values