diff --git a/src/api/ml/z3.ml b/src/api/ml/z3.ml
index d3a2d0e74..61a027cec 100644
--- a/src/api/ml/z3.ml
+++ b/src/api/ml/z3.ml
@@ -1260,6 +1260,8 @@ struct
   let mk_seq_length = Z3native.mk_seq_length
   let mk_seq_index = Z3native.mk_seq_index
   let mk_str_to_int = Z3native.mk_str_to_int
+  let mk_str_le = Z3native.mk_str_le
+  let mk_str_lt = Z3native.mk_str_lt
   let mk_int_to_str = Z3native.mk_int_to_str
   let mk_seq_to_re = Z3native.mk_seq_to_re
   let mk_seq_in_re = Z3native.mk_seq_in_re
diff --git a/src/api/ml/z3.mli b/src/api/ml/z3.mli
index 4dd280d77..bbfed07d2 100644
--- a/src/api/ml/z3.mli
+++ b/src/api/ml/z3.mli
@@ -1913,6 +1913,12 @@ sig
   (* retrieve integer expression encoded in string *)
   val mk_str_to_int : context -> Expr.expr -> Expr.expr
 
+  (* compare strings less-than-or-equal *)
+  val mk_str_le : context -> Expr.expr -> Expr.expr -> Expr.expr
+
+  (* compare strings less-than *)
+  val mk_str_lt : context -> Expr.expr -> Expr.expr -> Expr.expr
+
   (* convert an integer expression to a string *)
   val mk_int_to_str : context -> Expr.expr -> Expr.expr