diff --git a/lemon/config.h.cmake b/lemon/config.h.cmake
--- a/lemon/config.h.cmake
+++ b/lemon/config.h.cmake
@@ -2,3 +2,4 @@
 #cmakedefine HAVE_LP 1
 #cmakedefine HAVE_MIP 1
 #cmakedefine HAVE_GLPK 1
+#cmakedefine HAVE_CPLEX 1