diff --git a/src/tactic/sls/sls_engine.cpp b/src/tactic/sls/sls_engine.cpp
index 0e9112216..384270280 100644
--- a/src/tactic/sls/sls_engine.cpp
+++ b/src/tactic/sls/sls_engine.cpp
@@ -16,6 +16,7 @@ Author:
 Notes:
 
 --*/
+#include<float.h>
 #include<iomanip>
 
 #include"map.h"