diff --git a/common/matrix.hh b/common/matrix.hh
index 5f91c670dbcbc52152fea24952539b355716ee4c..457ed7728d7c0062f24e71a68052b2b0cd3b895b 100644
--- a/common/matrix.hh
+++ b/common/matrix.hh
@@ -79,12 +79,12 @@ namespace Dune {
     }
 
     /** \brief Return the number of rows */
-    size_type M() const {
+    size_type N() const {
       return rows_;
     }
 
     /** \brief Return the number of columns */
-    size_type N() const {
+    size_type M() const {
       return cols_;
     }