diff --git a/compiler/wasm32/nwasmcal.pas b/compiler/wasm32/nwasmcal.pas
index 77c26f096e..565bb2423b 100644
--- a/compiler/wasm32/nwasmcal.pas
+++ b/compiler/wasm32/nwasmcal.pas
@@ -70,8 +70,8 @@ implementation
           begin
             pvs:=tparavarsym(procdefinition.paras[paranr]);
             if is_wasm_reference_type(p.left.resultdef) and
-              (pvs.varspez in [vs_var,vs_constref]) or
-               ((pvs.varspez=vs_const) and (pvs.vardef.typ=formaldef)) then
+              ((pvs.varspez in [vs_var,vs_constref,vs_out]) or
+               ((pvs.varspez=vs_const) and (pvs.vardef.typ=formaldef))) then
               CGMessage(parser_e_wasm_ref_types_can_only_be_passed_by_value);
             Inc(paranr);
             p:=tcallparanode(tcallparanode(p).right);