diff --git a/core/Hexstring.cc b/core/Hexstring.cc
index 4cc988f06015f8fda8800e29f4578b1512d54824..c5d1af32efc5cad26a90121a0fb74a59f099fdc5 100644
--- a/core/Hexstring.cc
+++ b/core/Hexstring.cc
@@ -2071,7 +2071,7 @@ void HEXSTRING_template::set_param(Module_Param& param) {
       *this = operand1 + operand2;
     }
     else {
-      param.expr_type_error("a bitstring");
+      param.expr_type_error("a hexstring");
     }
     break;
   default: