diff --git a/dune/istl/colcompmatrix.hh b/dune/istl/colcompmatrix.hh
index 94b27d8c545eb8c03dd88661b5376f6dd4beca7c..36949a33dd57be2ca4089ea34b501b6c14225a31 100644
--- a/dune/istl/colcompmatrix.hh
+++ b/dune/istl/colcompmatrix.hh
@@ -298,7 +298,7 @@ namespace Dune
 
   template<class T, class A, int n, int m>
   ColCompMatrixInitializer<BCRSMatrix<FieldMatrix<T,n,m>,A> >::ColCompMatrixInitializer(ColCompMatrix& mat_)
-    : mat(&mat_), cols(mat_.N()), marker(0)
+    : mat(&mat_), cols(mat_.M()), marker(0)
   {
     mat->Nnz_=0;
   }