diff --git a/compiler.h b/compiler.h
index 962c2f531..1cd14d360 100644
--- a/compiler.h
+++ b/compiler.h
@@ -151,6 +151,16 @@ extern bool gn_io_range_error_flag;
    re-evaluated. */
 extern bool gn_strict_ca_eval_flag;
 
+/* If variables can be converted to uwires by a continuous assignment
+   (assuming no procedural assign, then return true. This will be true
+   for SystemVerilog */
+static inline bool gn_var_can_be_uwire(void)
+{
+      if (generation_flag == GN_VER2009)
+	    return true;
+      return false;
+}
+
 /* The bits of these GN_KEYWORDS_* constants define non-intersecting
    sets of keywords. The compiler enables groups of keywords by setting
    lexor_keyword_mask with the OR of the bits for the keywords to be
diff --git a/elab_net.cc b/elab_net.cc
index 06ef24b51..a9cdb25fa 100644
--- a/elab_net.cc
+++ b/elab_net.cc
@@ -414,6 +414,22 @@ NetNet* PEIdent::elaborate_lnet_common_(Design*des, NetScope*scope,
 
       assert(sig);
 
+	/* If this is SystemVerilog and the variable is not yet
+	   assigned by anything, then convert it to an unresolved
+	   wire. */
+      if (gn_var_can_be_uwire()
+	  && (sig->type() == NetNet::REG)
+	  && (sig->peek_eref() == 0) ) {
+	    sig->type(NetNet::UNRESOLVED_WIRE);
+      }
+
+      if (sig->type() == NetNet::UNRESOLVED_WIRE && sig->pin(0).is_linked()) {
+	    cerr << get_fileline() << ": error: Unresolved net " << sig->name()
+		 << " cannot have multiple drivers." << endl;
+	    des->errors += 1;
+	    return 0;
+      }
+
 	/* Don't allow registers as assign l-values. */
       if (sig->type() == NetNet::REG) {
 	    cerr << get_fileline() << ": error: reg " << sig->name()
diff --git a/netlist.cc b/netlist.cc
index 12d776f58..5727b6a81 100644
--- a/netlist.cc
+++ b/netlist.cc
@@ -78,7 +78,7 @@ ostream& operator<< (ostream&o, NetNet::Type t)
 	  case NetNet::WIRE:
 	    o << "wire";
 	    break;
-	  case NetNet::UWIRE:
+	  case NetNet::UNRESOLVED_WIRE:
 	    o << "uwire";
       }
       return o;
diff --git a/netlist.h b/netlist.h
index e2c165d92..fe07d9dfc 100644
--- a/netlist.h
+++ b/netlist.h
@@ -553,7 +553,7 @@ class NetNet  : public NetObj {
     public:
       enum Type { NONE, IMPLICIT, IMPLICIT_REG, INTEGER, WIRE, TRI, TRI1,
 		  SUPPLY0, SUPPLY1, WAND, TRIAND, TRI0, WOR, TRIOR, REG,
-		  UWIRE };
+		  UNRESOLVED_WIRE };
 
       enum PortType { NOT_A_PORT, PIMPLICIT, PINPUT, POUTPUT, PINOUT };
 
diff --git a/parse.y b/parse.y
index 502f6ac0a..7f7ba18d0 100644
--- a/parse.y
+++ b/parse.y
@@ -2708,12 +2708,12 @@ net_type
 	| K_supply1 { $$ = NetNet::SUPPLY1; }
 	| K_wor     { $$ = NetNet::WOR; }
 	| K_trior   { $$ = NetNet::TRIOR; }
-	| K_wone    { $$ = NetNet::UWIRE;
+	| K_wone    { $$ = NetNet::UNRESOLVED_WIRE;
 		      cerr << @1.text << ":" << @1.first_line << ": warning: "
 		              "'wone' is deprecated, please use 'uwire' "
 		              "instead." << endl;
 		    }
-	| K_uwire   { $$ = NetNet::UWIRE; }
+	| K_uwire   { $$ = NetNet::UNRESOLVED_WIRE; }
 	;
 
 var_type
diff --git a/t-dll.cc b/t-dll.cc
index f5d2771e9..a80bacb3e 100644
--- a/t-dll.cc
+++ b/t-dll.cc
@@ -2386,7 +2386,7 @@ void dll_target::signal(const NetNet*net)
 
 	      /* We will convert this to a TRI after we check that there
 		 is only one driver. */
-	  case NetNet::UWIRE:
+	  case NetNet::UNRESOLVED_WIRE:
 	    obj->type_ = IVL_SIT_UWIRE;
 	    break;