diff -r 4b3191b4970b -r cd8897f67c26 lemon/lp_glpk.h
--- a/lemon/lp_glpk.h	Mon Jul 17 07:30:56 2006 +0000
+++ b/lemon/lp_glpk.h	Mon Jul 17 09:00:21 2006 +0000
@@ -35,7 +35,7 @@
   /// 
   /// This class implements an interface for the GLPK LP solver.
   ///\ingroup gen_opt_group
-  class LpGlpk : public LpSolverBase {
+  class LpGlpk : virtual public LpSolverBase {
   protected:
     LPX* lp;