diff --git a/CMakeLists.txt b/CMakeLists.txt
index bfc5a1382..a45fff6a7 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -15,4 +15,4 @@ endif (CMAKE_COMPILER_IS_GNUCXX)
 include_directories( ${CMAKE_SOURCE_DIR} ${CMAKE_BINARY_DIR} )
 
 add_subdirectory(src)
-add_subdirectory(test)
\ No newline at end of file
+add_subdirectory(test)
diff --git a/src/MatrixBase.h b/src/MatrixBase.h
index 8e2be915b..bcc747aca 100644
--- a/src/MatrixBase.h
+++ b/src/MatrixBase.h
@@ -211,6 +211,16 @@ class MatrixBase
     MatrixBase() {};
 };
 
+template<typename Content>
+template<typename Derived>
+void MatrixXpr<Content>::operator=(const MatrixBase<Derived>& matrix)
+{
+  assert(rows() == matrix.rows() && cols() == matrix.cols());
+  for(int i = 0; i < rows(); i++)
+    for(int j = 0; j < cols(); j++)
+      this->operator()(i, j) = matrix(i, j);
+}
+
 template<typename Derived>
 std::ostream & operator <<
 ( std::ostream & s,
diff --git a/src/MatrixXpr.h b/src/MatrixXpr.h
index 0b23f88bf..9a1ab1085 100644
--- a/src/MatrixXpr.h
+++ b/src/MatrixXpr.h
@@ -105,6 +105,9 @@ template<typename Content> class MatrixXpr
           this->operator()(i, j) = other(i, j);
     }
     
+    template<typename Derived>
+    void operator=(const MatrixBase<Derived>& matrix);
+    
     MatrixXpr<MatrixRow<MatrixXpr<Content> > > row(int i);
     MatrixXpr<MatrixCol<MatrixXpr<Content> > > col(int i);
     MatrixXpr<MatrixMinor<MatrixXpr<Content> > > minor(int row, int col);