diff --git a/lemon/glpk.h b/lemon/glpk.h
--- a/lemon/glpk.h
+++ b/lemon/glpk.h
@@ -119,7 +119,7 @@
   ///
   /// This class implements an interface for the GLPK LP solver.
   ///\ingroup lp_group
-  class GlpkLp : public GlpkBase, public LpSolver {
+  class GlpkLp : public LpSolver, public GlpkBase {
   public:
 
     ///\e
@@ -127,6 +127,11 @@
     ///\e
     GlpkLp(const GlpkLp&);
 
+    ///\e
+    virtual GlpkLp* cloneSolver() const;
+    ///\e
+    virtual GlpkLp* newSolver() const;
+
   private:
 
     mutable std::vector<double> _primal_ray;
@@ -136,9 +141,6 @@
 
   protected:
 
-    virtual GlpkLp* _cloneSolver() const;
-    virtual GlpkLp* _newSolver() const;
-
     virtual const char* _solverName() const;
 
     virtual SolveExitStatus _solve();
@@ -203,7 +205,7 @@
   ///
   /// This class implements an interface for the GLPK MIP solver.
   ///\ingroup lp_group
-  class GlpkMip : public GlpkBase, public MipSolver {
+  class GlpkMip : public MipSolver, public GlpkBase {
   public:
 
     ///\e
@@ -211,11 +213,11 @@
     ///\e
     GlpkMip(const GlpkMip&);
 
+    virtual GlpkMip* cloneSolver() const;
+    virtual GlpkMip* newSolver() const;
+
   protected:
 
-    virtual GlpkMip* _cloneSolver() const;
-    virtual GlpkMip* _newSolver() const;
-
     virtual const char* _solverName() const;
 
     virtual ColTypes _getColType(int col) const;