diff --git a/src/api/ml/z3.ml b/src/api/ml/z3.ml
index 57db13f9d..cc7294aba 100644
--- a/src/api/ml/z3.ml
+++ b/src/api/ml/z3.ml
@@ -909,14 +909,13 @@ struct
     mk_sort ctx (Symbol.mk_string ctx name) constructors
 
   let mk_sort_ref (ctx: context) (name:Symbol.symbol) =
-    Z3native.mk_datatype_sort ctx name 0 [||]
+    Z3native.mk_datatype_sort ctx name 0 []
 
   let mk_sort_ref_s (ctx: context) (name: string) =
     mk_sort_ref ctx (Symbol.mk_string ctx name)
 
   let mk_sort_ref_p (ctx: context) (name:Symbol.symbol) (params:Sort.sort list) =
-    let param_array = Array.of_list params in
-    Z3native.mk_datatype_sort ctx name (List.length params) param_array
+    Z3native.mk_datatype_sort ctx name (List.length params) params
 
   let mk_sort_ref_ps (ctx: context) (name: string) (params:Sort.sort list) =
     mk_sort_ref_p ctx (Symbol.mk_string ctx name) params