diff --git a/matrix.cpp b/matrix.cpp
index dea7a429..3915c06c 100644
--- a/matrix.cpp
+++ b/matrix.cpp
@@ -27,15 +27,6 @@ using util::matrix;
 
 
 ///////////////////////////////////////////////////////////////////////////////
-template <size_t Rows, size_t Cols, typename T>
-matrix<Rows,Cols,T>&
-matrix<Rows,Cols,T>::invert (void)
-{
-    return *this = inverse ();
-}
-
-
-//-----------------------------------------------------------------------------
 //template <size_t S, typename T>
 //matrix<S,T>&
 //matrix<S,T>::invert_affine (void)
diff --git a/matrix.hpp b/matrix.hpp
index e66cf5a7..3443f754 100644
--- a/matrix.hpp
+++ b/matrix.hpp
@@ -50,9 +50,7 @@ namespace util {
         T determinant (void) const;
 
         matrix  inverse (void) const;
-        matrix& invert  (void);
         matrix  inverse_affine (void) const;
-        matrix& invert_affine  (void);
 
         vector<Rows,T> operator* (const vector<Rows,T>&) const;
         point<Rows,T>  operator* (const point<Rows,T> &) const;