diff --git a/src/tactic/sls/sls_tracker.h b/src/tactic/sls/sls_tracker.h
index 880e3a9f9..b675c15f4 100644
--- a/src/tactic/sls/sls_tracker.h
+++ b/src/tactic/sls/sls_tracker.h
@@ -26,6 +26,7 @@ Notes:
 #include"bv_decl_plugin.h"
 #include"model.h"
 
+#include"sls_params.hpp"
 #include"sls_powers.h"
 
 class sls_tracker {