diff --git a/elab_scope.cc b/elab_scope.cc
index 5f8d980e0..d8072ec04 100644
--- a/elab_scope.cc
+++ b/elab_scope.cc
@@ -336,8 +336,7 @@ static void blend_class_constructors(PClass*pclass)
 	// If we do not have an explicit constructor chain, but there
 	// is a parent class, then create an implicit chain.
       if (chain_new==0 && pclass->type->base_type!=0) {
-	    list<PExpr*>tmp_parms;
-	    chain_new = new PChainConstructor(tmp_parms);
+	    chain_new = new PChainConstructor(pclass->type->base_args);
 	    chain_new->set_line(*pclass);
       }
 
diff --git a/parse.y b/parse.y
index fbcded31f..29c3ea978 100644
--- a/parse.y
+++ b/parse.y
@@ -418,6 +418,11 @@ static void current_function_set_statement(const YYLTYPE&loc, vector<Statement*>
       property_qualifier_t property_qualifier;
       PPackage*package;
 
+      struct {
+	    data_type_t*type;
+	    list<PExpr*>*exprs;
+      } class_declaration_extends;
+
       verinum* number;
 
       verireal* realtime;
@@ -591,12 +596,13 @@ static void current_function_set_statement(const YYLTYPE&loc, vector<Statement*>
 %type <decl_assignments> list_of_variable_decl_assignments
 
 %type <data_type>  data_type data_type_or_implicit data_type_or_implicit_or_void
-%type <data_type>  class_declaration_extends_opt
 %type <class_type> class_identifier
 %type <struct_member>  struct_union_member
 %type <struct_members> struct_union_member_list
 %type <struct_type>    struct_data_type
 
+%type <class_declaration_extends> class_declaration_extends_opt
+
 %type <property_qualifier> class_item_qualifier property_qualifier
 %type <property_qualifier> class_item_qualifier_list property_qualifier_list
 %type <property_qualifier> class_item_qualifier_opt property_qualifier_opt
@@ -683,7 +689,7 @@ assignment_pattern /* IEEE1800-2005: A.6.7.1 */
 
 class_declaration /* IEEE1800-2005: A.1.2 */
   : K_virtual_opt K_class class_identifier class_declaration_extends_opt ';'
-      { pform_start_class_declaration(@2, $3, $4); }
+      { pform_start_class_declaration(@2, $3, $4.type, $4.exprs); }
     class_items_opt K_endclass
       { // Process a class.
 	pform_end_class_declaration(@8);
@@ -751,9 +757,15 @@ class_declaration_endlabel_opt
 
 class_declaration_extends_opt /* IEEE1800-2005: A.1.2 */
   : K_extends TYPE_IDENTIFIER
-      { $$ = $2; }
+      { $$.type = $2;
+	$$.exprs= 0;
+      }
+  | K_extends TYPE_IDENTIFIER '(' expression_list_with_nuls ')'
+      { $$.type  = $2;
+	$$.exprs = $4;
+      }
   |
-      { $$ = 0; }
+      { $$.type = 0; $$.exprs = 0; }
   ;
 
   /* The class_items_opt and class_items rules together implement the
diff --git a/pform.h b/pform.h
index 70db36c87..420f437bd 100644
--- a/pform.h
+++ b/pform.h
@@ -182,7 +182,8 @@ extern void pform_endmodule(const char*, bool inside_celldefine,
 
 extern void pform_start_class_declaration(const struct vlltype&loc,
 					  class_type_t*type,
-					  data_type_t*base_type);
+					  data_type_t*base_type,
+					  std::list<PExpr*>*base_exprs);
 extern void pform_class_property(const struct vlltype&loc,
 				 property_qualifier_t pq,
 				 data_type_t*data_type,
diff --git a/pform_dump.cc b/pform_dump.cc
index 845fa5477..26d8c5b98 100644
--- a/pform_dump.cc
+++ b/pform_dump.cc
@@ -180,10 +180,22 @@ void struct_type_t::pform_dump(ostream&out, unsigned indent) const
 
 void class_type_t::pform_dump(ostream&out, unsigned indent) const
 {
-      out << setw(indent) << "" << "class " << name << " {";
+      out << setw(indent) << "" << "class " << name;
 
-      if (base_type) out << " (extends)";
+      if (base_type) out << " extends <type>";
+      if (base_args.size() > 0) {
+	    out << " (";
+	    for (list<PExpr*>::const_iterator cur = base_args.begin()
+		       ; cur != base_args.end() ; ++cur) {
+		  const PExpr*curp = *cur;
+		  if (cur != base_args.begin())
+			out << ", ";
+		  curp->dump(out);
+	    }
+	    out << ")";
+      }
 
+      out << " {";
       for (map<perm_string,prop_info_t>::const_iterator cur = properties.begin()
 		 ; cur != properties.end() ; ++cur) {
 	    out << " " << cur->first;
diff --git a/pform_pclass.cc b/pform_pclass.cc
index f3da71dda..3b7b94d59 100644
--- a/pform_pclass.cc
+++ b/pform_pclass.cc
@@ -26,7 +26,17 @@
  */
 static PClass*pform_cur_class = 0;
 
-void pform_start_class_declaration(const struct vlltype&loc, class_type_t*type, data_type_t*base_type)
+/*
+ * The base_type is set to the base class if this declaration is
+ * starting a derived class. For example, for the syntax:
+ *
+ *    class foo extends bar (exprs) ...
+ *
+ * the base_type is the type of the class "bar", and the base_exprs,
+ * if present, are the "exprs" that would be passed to a chained
+ * constructor.
+ */
+void pform_start_class_declaration(const struct vlltype&loc, class_type_t*type, data_type_t*base_type, list<PExpr*>*base_exprs)
 {
       PClass*class_scope = pform_push_class_scope(loc, type->name);
       class_scope->type = type;
@@ -35,6 +45,15 @@ void pform_start_class_declaration(const struct vlltype&loc, class_type_t*type,
 
       assert(type->base_type == 0);
       type->base_type = base_type;
+
+      assert(type->base_args.size() == 0);
+      if (base_exprs) {
+	    for (list<PExpr*>::iterator cur = base_exprs->begin()
+		       ; cur != base_exprs->end() ; ++ cur) {
+		  type->base_args.push_back(*cur);
+	    }
+	    delete base_exprs;
+      }
 }
 
 void pform_class_property(const struct vlltype&loc,
diff --git a/pform_types.h b/pform_types.h
index 5619e6d39..84700275c 100644
--- a/pform_types.h
+++ b/pform_types.h
@@ -235,8 +235,10 @@ struct class_type_t : public data_type_t {
 
 	// This is the named type that is supposed to be the base
 	// class that we are extending. This is nil if there is no
-	// hierarchy.
+	// hierarchy. If there are arguments to the base class, then
+	// put them in the base_args vector.
       data_type_t*base_type;
+      std::list<PExpr*>base_args;
 
 	// This is a map of the properties. Map the name to the type.
       struct prop_info_t {