diff --git a/include/boost/astronomy/coordinate/io.hpp b/include/boost/astronomy/coordinate/io.hpp
index a55fd379..b677638a 100644
--- a/include/boost/astronomy/coordinate/io.hpp
+++ b/include/boost/astronomy/coordinate/io.hpp
@@ -129,7 +129,7 @@ std::ostream& operator<< (std::ostream &out, spherical_differential
     return out;
 }
 
-//!"<<" operator overload to print details of a spherical_coslat_differential
+//!"<<" operator overload to print details of a spherical_coslat_differential point
 template
 <
     typename CoordinateType,
@@ -148,4 +148,4 @@ std::ostream& operator<< (std::ostream &out, spherical_coslat_differential
     return out;
 }
 }}} //namespace boost::astronomy::coordinate
-#endif // !BOOST_ASTRONOMY_COORDINATE_IO_HPP
\ No newline at end of file
+#endif // !BOOST_ASTRONOMY_COORDINATE_IO_HPP