diff --git a/src/tactic/sls/sls_tracker.h b/src/tactic/sls/sls_tracker.h
index 186fae250..73355197a 100644
--- a/src/tactic/sls/sls_tracker.h
+++ b/src/tactic/sls/sls_tracker.h
@@ -25,6 +25,7 @@ Notes:
 #include"bv_decl_plugin.h"
 #include"model.h"
 
+#include"sls_params.hpp"
 #include"sls_powers.h"
 
 class sls_tracker {
@@ -1052,4 +1053,4 @@ public:
     }
 };
 
-#endif
\ No newline at end of file
+#endif