diff --git a/modules/conop/src/rule_based.cc b/modules/conop/src/rule_based.cc
index 98018f29f3a2cf1c3a0d56c7fb967078e09c4c3c..dffb8c8c411e247338b65dc27efbd89c34eee1fd 100644
--- a/modules/conop/src/rule_based.cc
+++ b/modules/conop/src/rule_based.cc
@@ -16,6 +16,7 @@
 // along with this library; if not, write to the Free Software Foundation, Inc.,
 // 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
 //------------------------------------------------------------------------------
+#include <limits>
 #include <ost/log.hh>
 #include <ost/profile.hh>
 #include <ost/mol/xcs_editor.hh>