diff --git a/include/libsemigroups/sims.hpp b/include/libsemigroups/sims.hpp
index 1eb649f2a..9bc7853bf 100644
--- a/include/libsemigroups/sims.hpp
+++ b/include/libsemigroups/sims.hpp
@@ -2529,7 +2529,7 @@ namespace libsemigroups {
     cbegin_right_generating_pairs(Presentation<word_type> const& p,
                                   WordGraph<Node> const&         wg) {
       validate_right_congruence(p, wg);
-      return cbegin_right_generating_pairs(p, wg);
+      return cbegin_right_generating_pairs_no_checks(p, wg);
     }
 
     //! \ingroup congruences_group
@@ -3241,7 +3241,7 @@ namespace libsemigroups {
   class SimsRefinerIdeals {
    private:
     using node_type    = uint32_t;
-    using KnuthBendix_ = KnuthBendix<detail::RewriteFromLeft>;
+    using KnuthBendix_ = KnuthBendix<>;
     std::vector<KnuthBendix_> _knuth_bendices;
 
    public:
diff --git a/src/sims.cpp b/src/sims.cpp
index ca590e10d..f2c6c21cc 100644
--- a/src/sims.cpp
+++ b/src/sims.cpp
@@ -1459,7 +1459,7 @@ namespace libsemigroups {
 
   }  // namespace sims
 
-  [[nodiscard]] std::string to_human_readable_repr(SimsStats const& x) {
+  [[nodiscard]] std::string to_human_readable_repr(SimsStats const&) {
     return fmt::format("<SimsStats object>");
   }