diff --git a/src/sat/sat_solver_core.h b/src/sat/sat_solver_core.h
index 4f763bd55..619a3e3a0 100644
--- a/src/sat/sat_solver_core.h
+++ b/src/sat/sat_solver_core.h
@@ -32,7 +32,7 @@ namespace sat {
         ~solver_core() {}
 
         virtual void pop_to_base_level() {}
-        virtual bool  at_base_lvl() const { return true; }
+        virtual bool at_base_lvl() const { return true; }
 
         // retrieve model if solver return sat
         virtual model const & get_model() const = 0;