diff --git a/pform.cc b/pform.cc
index 142df2c66..fb8b73534 100644
--- a/pform.cc
+++ b/pform.cc
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 1998-2022 Stephen Williams (steve@icarus.com)
+ * Copyright (c) 1998-2024 Stephen Williams (steve@icarus.com)
  * Copyright CERN 2013 / Stephen Williams (steve@icarus.com)
  *
  *    This source code is free software; you can redistribute it
@@ -3368,6 +3368,12 @@ void pform_check_net_data_type(const struct vlltype&loc, NetNet::Type net_type,
       if (vec_type && vec_type->implicit_flag)
 	    return;
 
+      if (!gn_cadence_types_flag)
+	    VLerror(loc, "Net data type requires SystemVerilog or -gxtypes.");
+
+      if (vec_type)
+	    return;
+
       const real_type_t*rtype = dynamic_cast<const real_type_t*>(data_type);
       if (rtype && rtype->type_code() == real_type_t::REAL)
 	    return;