diff --git a/libguile/objects.h b/libguile/objects.h
index 8f778838c..3774d8f70 100644
--- a/libguile/objects.h
+++ b/libguile/objects.h
@@ -89,6 +89,7 @@
 #define SCM_OPERATOR_PROC_1(obj) (SCM_OBJ_OPERATOR_CLASS (obj)->proc1)
 #define SCM_OPERATOR_PROC_2(obj) (SCM_OBJ_OPERATOR_CLASS (obj)->proc2)
 #define SCM_OPERATOR_PROC_3(obj) (SCM_OBJ_OPERATOR_CLASS (obj)->proc3)
+#define SCM_OPERATOR_SETTER(obj) (SCM_OBJ_OPERATOR_CLASS (obj)->setter)
 
 #define SCM_I_ENTITYP(obj)\
 ((SCM_OBJ_CLASS_FLAGS (obj) & SCM_CLASSF_ENTITY) != 0)
@@ -96,6 +97,7 @@
 #define SCM_ENTITY_PROC_1(obj) (SCM_STRUCT_DATA (obj)[scm_struct_i_proc + 1])
 #define SCM_ENTITY_PROC_2(obj) (SCM_STRUCT_DATA (obj)[scm_struct_i_proc + 2])
 #define SCM_ENTITY_PROC_3(obj) (SCM_STRUCT_DATA (obj)[scm_struct_i_proc + 3])
+#define SCM_ENTITY_SETTER(obj) (SCM_STRUCT_DATA (obj)[scm_struct_i_setter])
 
 /* {Operator classes}
  *
@@ -137,7 +139,7 @@ struct scm_metaclass_standard {
   SCM print;
 };
 
-#define SCM_METACLASS_OPERATOR_LAYOUT "popopopo"
+#define SCM_METACLASS_OPERATOR_LAYOUT "popopopopo"
 struct scm_metaclass_operator {
   SCM layout;
   SCM vcell;
@@ -147,6 +149,7 @@ struct scm_metaclass_operator {
   SCM proc1;
   SCM proc2;
   SCM proc3;
+  SCM setter;
 };
 
 /* {Entity classes}
@@ -159,9 +162,28 @@ struct scm_metaclass_operator {
  */
 #define SCM_ENTITY_LAYOUT ""
 
+/* The following three definitions are Goops dependencies needed by
+   scm_class_of. */
+#define SCM_CLASSF_GOOPS       (0x10 << 24)
+#define scm_si_redefined       18
+#define scm_si_hashsets        20
+#define SCM_CLASS_OF(x)        SCM_STRUCT_VTABLE (x)
+
+#define SCM_OBJ_CLASS_REDEF(x) (SCM_STRUCT_VTABLE_DATA(x)[scm_si_redefined])
+
 extern SCM scm_metaclass_standard;
 extern SCM scm_metaclass_operator;
+extern SCM scm_class_boolean, scm_class_char, scm_class_pair;
+extern SCM scm_class_procedure, scm_class_string, scm_class_symbol;
+extern SCM scm_class_procedure_with_setter;
+extern SCM scm_class_vector, scm_class_null;
+extern SCM scm_class_real, scm_class_complex, scm_class_integer;
+extern SCM scm_class_keyword, scm_class_unknown;
 
+extern void (*scm_change_object_class) (SCM, SCM, SCM);
+extern void (*scm_memoize_method) (SCM x, SCM args);
+
+extern SCM scm_class_of (SCM obj);
 extern SCM scm_entity_p (SCM obj);
 extern SCM scm_set_object_procedure_x (SCM obj, SCM procs);
 extern SCM scm_make_class_object (SCM metaclass, SCM layout);