diff --git a/src/sat/base_types_.ml b/src/sat/base_types_.ml
index 7e6843dd..e298c545 100644
--- a/src/sat/base_types_.ml
+++ b/src/sat/base_types_.ml
@@ -1,5 +1,4 @@
 open Sidekick_core
-open Sigs
 
 (* a boolean variable (positive int) *)
 module Var0 : sig