diff --git a/elab_scope.cc b/elab_scope.cc
index 826154eae..99a14081d 100644
--- a/elab_scope.cc
+++ b/elab_scope.cc
@@ -496,29 +496,30 @@ static void elaborate_scope_class(Design*des, NetScope*scope, PClass*pclass)
 		 << endl;
       }
 
-      class_type_t*base_class = dynamic_cast<class_type_t*> (use_type->base_type);
-      if (use_type->base_type && !base_class) {
-	    cerr << pclass->get_fileline() << ": error: "
-		 << "Base type of " << use_type->name
-		 << " is not a class." << endl;
-	    des->errors += 1;
-      }
 
-      netclass_t*use_base_class = 0;
-      if (base_class) {
-	    use_base_class = base_class->save_elaborated_type;
-	    if (use_base_class == 0) {
+      const netclass_t*use_base_class = 0;
+      if (use_type->base_type) {
+	    ivl_type_t base_type = use_type->base_type->elaborate_type(des, scope);
+	    use_base_class = dynamic_cast<const netclass_t *>(base_type);
+	    if (!use_base_class) {
 		  cerr << pclass->get_fileline() << ": error: "
-		       << "Base class " << base_class->name
-		       << " not found." << endl;
+		       << "Base type of " << use_type->name
+		       << " is not a class." << endl;
 		  des->errors += 1;
 	    }
       }
 
       netclass_t*use_class = new netclass_t(use_type->name, use_base_class);
 
-      ivl_assert(*pclass, use_type->save_elaborated_type == 0);
-      use_type->save_elaborated_type = use_class;
+      // If this is a package we need to remember the elaborated type so that
+      // scoped type references work. Since there is only one instance for each
+      // package this works. For classes defined in modules there might be
+      // multiple instances though. Each module instance will have its own class
+      // type instance, so the same does not work there.
+      if (scope->type() == NetScope::PACKAGE) {
+	    ivl_assert(*pclass, use_type->save_elaborated_type == 0);
+	    use_type->save_elaborated_type = use_class;
+      }
 
       NetScope*class_scope = new NetScope(scope, hname_t(pclass->pscope_name()),
 					  NetScope::CLASS, scope->unit());
diff --git a/elab_type.cc b/elab_type.cc
index 948836856..ecd81e098 100644
--- a/elab_type.cc
+++ b/elab_type.cc
@@ -101,10 +101,11 @@ ivl_type_t atom2_type_t::elaborate_type_raw(Design*des, NetScope*) const
       }
 }
 
-ivl_type_t class_type_t::elaborate_type_raw(Design*, NetScope*) const
+ivl_type_t class_type_t::elaborate_type_raw(Design*des, NetScope*scope) const
 {
-      ivl_assert(*this, save_elaborated_type);
-      return save_elaborated_type;
+      if (save_elaborated_type)
+	    return save_elaborated_type;
+      return scope->find_class(des, name);
 }
 
 /*
diff --git a/ivtest/ivltests/sv_class_in_module_decl.v b/ivtest/ivltests/sv_class_in_module_decl.v
new file mode 100644
index 000000000..267bed7b9
--- /dev/null
+++ b/ivtest/ivltests/sv_class_in_module_decl.v
@@ -0,0 +1,32 @@
+// Check that it is possible to have multiple instances of a module that defines
+// a class and that the actual class types can have different implementations
+// based on module parameters.
+
+module M #(
+  parameter X = 0
+);
+
+  class C;
+    function int f;
+      return X;
+    endfunction
+  endclass
+
+  C c = new;
+
+endmodule
+
+module test;
+
+  M #(10) m1();
+  M #(20) m2();
+
+  initial begin
+    if (m1.c.f() == 10 && m2.c.f() == 20) begin
+      $display("PASSED");
+    end else begin
+      $display("FAILED");
+    end
+  end
+
+endmodule
diff --git a/ivtest/regress-sv.list b/ivtest/regress-sv.list
index 291377749..43fb411a0 100644
--- a/ivtest/regress-sv.list
+++ b/ivtest/regress-sv.list
@@ -478,6 +478,7 @@ sv_class_empty_item	normal,-g2009		ivltests
 sv_class_extends_scoped	normal,-g2009		ivltests
 sv_class_localparam	normal,-g2009		ivltests
 sv_class_new_init	normal,-g2009		ivltests
+sv_class_in_module_decl	normal,-g2009		ivltests
 sv_darray1		normal,-g2009		ivltests
 sv_darray2		normal,-g2009		ivltests
 sv_darray3		normal,-g2009		ivltests
diff --git a/ivtest/regress-vlog95.list b/ivtest/regress-vlog95.list
index 8357e0afc..d4b6a7303 100644
--- a/ivtest/regress-vlog95.list
+++ b/ivtest/regress-vlog95.list
@@ -376,6 +376,7 @@ sv_class_empty_item	CE,-g2009		ivltests
 sv_class_extends_scoped	CE,-g2009		ivltests
 sv_class_localparam	CE,-g2009		ivltests
 sv_class_new_init	CE,-g2009		ivltests
+sv_class_in_module_decl	CE,-g2009		ivltests
 sv_end_label		CE,-g2009		ivltests  # Also generate
 sv_foreach2		CE,-g2009,-pallowsigned=1	ivltests
 sv_foreach3		CE,-g2009		ivltests
diff --git a/netclass.cc b/netclass.cc
index 82be2c55e..3365a8949 100644
--- a/netclass.cc
+++ b/netclass.cc
@@ -23,8 +23,8 @@
 
 using namespace std;
 
-netclass_t::netclass_t(perm_string name, netclass_t*sup)
-: name_(name), super_(sup), class_scope_(0), definition_scope_(0)
+netclass_t::netclass_t(perm_string name, const netclass_t*super)
+: name_(name), super_(super), class_scope_(0), definition_scope_(0)
 {
 }
 
diff --git a/netclass.h b/netclass.h
index 7274bd5f7..af473ba71 100644
--- a/netclass.h
+++ b/netclass.h
@@ -35,7 +35,7 @@ class PExpr;
 
 class netclass_t : public ivl_type_s {
     public:
-      netclass_t(perm_string class_name, netclass_t*par);
+      netclass_t(perm_string class_name, const netclass_t*super);
       ~netclass_t();
 
 	// Set the property of the class during elaboration. Set the
@@ -120,7 +120,7 @@ class netclass_t : public ivl_type_s {
       perm_string name_;
 	// If this is derived from another base class, point to it
 	// here.
-      netclass_t*super_;
+      const netclass_t*super_;
 	// Map property names to property table index.
       std::map<perm_string,size_t> properties_;
 	// Vector of properties.