diff --git a/Math/Matrix/Matrix.php b/Math/Matrix/Matrix.php
index 844ce89e0..95b67cd4d 100755
--- a/Math/Matrix/Matrix.php
+++ b/Math/Matrix/Matrix.php
@@ -742,7 +742,7 @@ class Matrix implements \ArrayAccess, \Iterator
     }
 
     /**
-     * Sum the elements in the matrix
+     * Sum the elements in the matrix.
      *
      * @param int $axis Axis (-1 -> all dimensions, 0 -> columns, 1 -> rows)
      *