diff --git a/lemon/config.h.in b/lemon/config.h.in
--- a/lemon/config.h.in
+++ b/lemon/config.h.in
@@ -9,3 +9,6 @@
 
 /* Define to 1 if you have GLPK. */
 #undef HAVE_GLPK
+
+/* Define to 1 if you have SOPLEX */
+#undef HAVE_SOPLEX
\ No newline at end of file