diff --git a/doc/src/region.rst b/doc/src/region.rst
index 7b95831249..4a6f5ae3b8 100644
--- a/doc/src/region.rst
+++ b/doc/src/region.rst
@@ -214,7 +214,7 @@ the cylinder axes can be specified as a equal-style variable.  For styles
 *cone* and *plane* all properties can be defined via equal-style variables.
 For style *plane*, there is the restriction that all three components
 of the direction normal to the plane should be either constant or
-defined via equal-style variables. 
+defined via equal-style variables.
 
 If the value is a variable, it should be specified as v_name, where
 name is the variable name.  In this case, the variable will be