diff --git a/include/igloo/filter.h b/include/igloo/filter.h
index 56c2542..d282b08 100644
--- a/include/igloo/filter.h
+++ b/include/igloo/filter.h
@@ -67,7 +67,7 @@ typedef struct {
  *  name, associated
  *      See refobject_new().
  */
-igloo_filter_t * igloo_filter_new(const igloo_filter_ifdesc_t *ifdesc, igloo_ro_t backend_object, void *backend_userdata, const char *name, igloo_ro_t associated);
+igloo_filter_t * igloo_filter_new(const igloo_filter_ifdesc_t *ifdesc, igloo_ro_t backend_object, void *backend_userdata, const char *name, igloo_ro_t associated, igloo_ro_t instance);
 
 /* This tests a object according to the filter.
  * Parameters:
diff --git a/include/igloo/io.h b/include/igloo/io.h
index 4f6de8c..e815fb9 100644
--- a/include/igloo/io.h
+++ b/include/igloo/io.h
@@ -130,7 +130,7 @@ typedef struct {
  *  name, associated
  *      See refobject_new().
  */
-igloo_io_t * igloo_io_new(const igloo_io_ifdesc_t *ifdesc, igloo_ro_t backend_object, void *backend_userdata, const char *name, igloo_ro_t associated);
+igloo_io_t * igloo_io_new(const igloo_io_ifdesc_t *ifdesc, igloo_ro_t backend_object, void *backend_userdata, const char *name, igloo_ro_t associated, igloo_ro_t instance);
 
 /* Read data from a IO handle.
  * Parameters:
diff --git a/include/igloo/logmsg.h b/include/igloo/logmsg.h
index e537b9e..c643817 100644
--- a/include/igloo/logmsg.h
+++ b/include/igloo/logmsg.h
@@ -164,7 +164,7 @@ int igloo_logmsg_get_extra(igloo_logmsg_t *msg, igloo_logmsg_opt_t *options, igl
  *  name, associated
  *      See refobject_new().
  */
-igloo_objecthandler_t 	* igloo_logmsg_formarter(igloo_ro_t backend, const char *subformat, const char *name, igloo_ro_t associated);
+igloo_objecthandler_t 	* igloo_logmsg_formarter(igloo_ro_t backend, const char *subformat, const char *name, igloo_ro_t associated, igloo_ro_t instance);
 
 /* This creates a filter for log messages.
  * Parameters:
@@ -185,7 +185,7 @@ igloo_objecthandler_t 	* igloo_logmsg_formarter(igloo_ro_t backend, const char *
  *  name, associated
  *      See refobject_new().
  */
-igloo_filter_t 		* igloo_logmsg_filter(igloo_loglevel_t level_min, igloo_loglevel_t level_max, igloo_logmsg_opt_t options_required, igloo_logmsg_opt_t options_absent, const struct timespec * ts_min, const struct timespec * ts_max, const char *cat, const char *name, igloo_ro_t associated);
+igloo_filter_t 		* igloo_logmsg_filter(igloo_loglevel_t level_min, igloo_loglevel_t level_max, igloo_logmsg_opt_t options_required, igloo_logmsg_opt_t options_absent, const struct timespec * ts_min, const struct timespec * ts_max, const char *cat, const char *name, igloo_ro_t associated, igloo_ro_t instance);
 
 #ifdef __cplusplus
 }
diff --git a/include/igloo/objecthandler.h b/include/igloo/objecthandler.h
index f541c42..0e20ba2 100644
--- a/include/igloo/objecthandler.h
+++ b/include/igloo/objecthandler.h
@@ -71,7 +71,7 @@ typedef struct {
  *  name, associated
  *      See refobject_new().
  */
-igloo_objecthandler_t * igloo_objecthandler_new(const igloo_objecthandler_ifdesc_t *ifdesc, igloo_ro_t backend_object, void *backend_userdata, const char *name, igloo_ro_t associated);
+igloo_objecthandler_t * igloo_objecthandler_new(const igloo_objecthandler_ifdesc_t *ifdesc, igloo_ro_t backend_object, void *backend_userdata, const char *name, igloo_ro_t associated, igloo_ro_t instance);
 
 /* This handles a object according to the filter.
  * Parameters:
diff --git a/include/igloo/ro.h b/include/igloo/ro.h
index df522b5..7b4cea4 100644
--- a/include/igloo/ro.h
+++ b/include/igloo/ro.h
@@ -287,12 +287,12 @@ int             igloo_RO_HAS_TYPE_raw(igloo_ro_t object, const igloo_ro_type_t *
  * the associated refobject is given by associated.
  */
 
-igloo_ro_t      igloo_ro_new__raw(const igloo_ro_type_t *type, const char *name, igloo_ro_t associated);
-#define         igloo_ro_new_raw(type, name, associated)  igloo_RO_TO_TYPE(igloo_ro_new__raw(igloo_RO_GET_TYPE_BY_SYMBOL(type), (name), (associated)), type)
+igloo_ro_t      igloo_ro_new__raw(const igloo_ro_type_t *type, const char *name, igloo_ro_t associated, igloo_ro_t instance);
+#define         igloo_ro_new_raw(type, name, associated)  igloo_RO_TO_TYPE(igloo_ro_new__raw(igloo_RO_GET_TYPE_BY_SYMBOL(type), (name), (associated), igloo_RO_NULL), type)
 
-igloo_ro_t      igloo_ro_new__simple(const igloo_ro_type_t *type, const char *name, igloo_ro_t associated, ...);
-#define         igloo_ro_new(type, ...)                         igloo_RO_TO_TYPE(igloo_ro_new__simple(igloo_RO_GET_TYPE_BY_SYMBOL(type), NULL, igloo_RO_NULL, ## __VA_ARGS__), type)
-#define         igloo_ro_new_ext(type, name, associated, ...)   igloo_RO_TO_TYPE(igloo_ro_new__simple(igloo_RO_GET_TYPE_BY_SYMBOL(type), (name), (associated), ## __VA_ARGS__), type)
+igloo_ro_t      igloo_ro_new__simple(const igloo_ro_type_t *type, const char *name, igloo_ro_t associated, igloo_ro_t instance, ...);
+#define         igloo_ro_new(type, ...)                         igloo_RO_TO_TYPE(igloo_ro_new__simple(igloo_RO_GET_TYPE_BY_SYMBOL(type), NULL, igloo_RO_NULL, igloo_RO_NULL, ## __VA_ARGS__), type)
+#define         igloo_ro_new_ext(type, name, associated, ...)   igloo_RO_TO_TYPE(igloo_ro_new__simple(igloo_RO_GET_TYPE_BY_SYMBOL(type), (name), (associated), igloo_RO_NULL, ## __VA_ARGS__), type)
 
 /* This increases the reference counter of the object */
 igloo_error_t   igloo_ro_ref(igloo_ro_t self);
diff --git a/include/igloo/stdio.h b/include/igloo/stdio.h
index cb00917..64dcf4e 100644
--- a/include/igloo/stdio.h
+++ b/include/igloo/stdio.h
@@ -31,7 +31,7 @@ extern "C" {
 
 #include "io.h"
 
-igloo_io_t * igloo_stdio_new_file(const char *filename, const char *mode, const char *name, igloo_ro_t associated);
+igloo_io_t * igloo_stdio_new_file(const char *filename, const char *mode, const char *name, igloo_ro_t associated, igloo_ro_t instance);
 
 #ifdef __cplusplus
 }
diff --git a/src/filter.c b/src/filter.c
index 0a4e923..8189e49 100644
--- a/src/filter.c
+++ b/src/filter.c
@@ -22,9 +22,9 @@ igloo_RO_PUBLIC_TYPE(igloo_filter_t,
         igloo_RO_TYPEDECL_FREE(igloo_interface_base_free)
         );
 
-igloo_filter_t * igloo_filter_new(const igloo_filter_ifdesc_t *ifdesc, igloo_ro_t backend_object, void *backend_userdata, const char *name, igloo_ro_t associated)
+igloo_filter_t * igloo_filter_new(const igloo_filter_ifdesc_t *ifdesc, igloo_ro_t backend_object, void *backend_userdata, const char *name, igloo_ro_t associated, igloo_ro_t instance)
 {
-    return igloo_interface_base_new(igloo_filter_t, ifdesc, backend_object, backend_userdata, name, associated);
+    return igloo_interface_base_new(igloo_filter_t, ifdesc, backend_object, backend_userdata, name, associated, instance);
 }
 
 igloo_filter_result_t igloo_filter_test(igloo_filter_t *filter, igloo_ro_t object)
diff --git a/src/interface.c b/src/interface.c
index 13622d1..099546b 100644
--- a/src/interface.c
+++ b/src/interface.c
@@ -31,7 +31,7 @@ void igloo_interface_base_free(igloo_ro_t self)
         free(iface->backend_userdata);
 }
 
-igloo_ro_t igloo_interface_base_new_real(const igloo_ro_type_t *type, size_t description_length, const igloo_interface_base_ifdesc_t *ifdesc, igloo_ro_t backend_object, void *backend_userdata, const char *name, igloo_ro_t associated)
+igloo_ro_t igloo_interface_base_new_real(const igloo_ro_type_t *type, size_t description_length, const igloo_interface_base_ifdesc_t *ifdesc, igloo_ro_t backend_object, void *backend_userdata, const char *name, igloo_ro_t associated, igloo_ro_t instance)
 {
     igloo_ro_t self;
     igloo__interface_base_t *base;
@@ -42,7 +42,7 @@ igloo_ro_t igloo_interface_base_new_real(const igloo_ro_type_t *type, size_t des
     if (ifdesc->base_length != sizeof(igloo_interface_base_ifdesc_t) || ifdesc->base_version != igloo_INTERFACE_DESCRIPTION_BASE__VERSION || ifdesc->description_length != description_length)
         return igloo_RO_NULL;
 
-    self = igloo_ro_new__raw(type, name, associated);
+    self = igloo_ro_new__raw(type, name, associated, instance);
     base = igloo_INTERFACE_CAST(self);
 
     if (igloo_RO_IS_NULL(self))
diff --git a/src/io.c b/src/io.c
index 1ae625d..b65aa35 100644
--- a/src/io.c
+++ b/src/io.c
@@ -44,9 +44,9 @@ igloo_RO_PUBLIC_TYPE(igloo_io_t,
         );
 
 
-igloo_io_t * igloo_io_new(const igloo_io_ifdesc_t *ifdesc, igloo_ro_t backend_object, void *backend_userdata, const char *name, igloo_ro_t associated)
+igloo_io_t * igloo_io_new(const igloo_io_ifdesc_t *ifdesc, igloo_ro_t backend_object, void *backend_userdata, const char *name, igloo_ro_t associated, igloo_ro_t instance)
 {
-    igloo_io_t *io = igloo_interface_base_new(igloo_io_t, ifdesc, backend_object, backend_userdata, name, associated);
+    igloo_io_t *io = igloo_interface_base_new(igloo_io_t, ifdesc, backend_object, backend_userdata, name, associated, instance);
     if (!io)
         return NULL;
 
diff --git a/src/logmsg.c b/src/logmsg.c
index b248997..adf418f 100644
--- a/src/logmsg.c
+++ b/src/logmsg.c
@@ -270,7 +270,7 @@ static const igloo_objecthandler_ifdesc_t igloo_logmsg_formarter_ifdesc = {
     .set_backend = __set_backend
 };
 
-igloo_objecthandler_t   * igloo_logmsg_formarter(igloo_ro_t backend, const char *subformat, const char *name, igloo_ro_t associated)
+igloo_objecthandler_t   * igloo_logmsg_formarter(igloo_ro_t backend, const char *subformat, const char *name, igloo_ro_t associated, igloo_ro_t instance)
 {
     igloo_logmsg_formarter_subtype_t *sf = NULL;
     igloo_objecthandler_t *objecthandler;
@@ -293,7 +293,7 @@ igloo_objecthandler_t   * igloo_logmsg_formarter(igloo_ro_t backend, const char
         return NULL;
     }
 
-    objecthandler = igloo_objecthandler_new(&igloo_logmsg_formarter_ifdesc, NULL, sf, name, associated);
+    objecthandler = igloo_objecthandler_new(&igloo_logmsg_formarter_ifdesc, NULL, sf, name, associated, instance);
     if (!objecthandler) {
         free(sf);
     }
@@ -354,7 +354,7 @@ static const igloo_filter_ifdesc_t igloo_logmsg_filter_ifdesc = {
     .test = __test
 };
 
-igloo_filter_t          * igloo_logmsg_filter(igloo_loglevel_t level_min, igloo_loglevel_t level_max, igloo_logmsg_opt_t options_required, igloo_logmsg_opt_t options_absent, const struct timespec * ts_min, const struct timespec * ts_max, const char *cat, const char *name, igloo_ro_t associated)
+igloo_filter_t          * igloo_logmsg_filter(igloo_loglevel_t level_min, igloo_loglevel_t level_max, igloo_logmsg_opt_t options_required, igloo_logmsg_opt_t options_absent, const struct timespec * ts_min, const struct timespec * ts_max, const char *cat, const char *name, igloo_ro_t associated, igloo_ro_t instance)
 {
     igloo_filter_t *filter;
     igloo_logmsg_filter_mask_t *mask = calloc(1, sizeof(*mask));
@@ -386,7 +386,7 @@ igloo_filter_t          * igloo_logmsg_filter(igloo_loglevel_t level_min, igloo_
         }
     }
 
-    filter = igloo_filter_new(&igloo_logmsg_filter_ifdesc, igloo_RO_NULL, mask, name, associated);
+    filter = igloo_filter_new(&igloo_logmsg_filter_ifdesc, igloo_RO_NULL, mask, name, associated, instance);
     if (!filter) {
         free(mask);
     }
diff --git a/src/objecthandler.c b/src/objecthandler.c
index bee50a2..0ec03bc 100644
--- a/src/objecthandler.c
+++ b/src/objecthandler.c
@@ -44,9 +44,9 @@ igloo_RO_PUBLIC_TYPE(igloo_objecthandler_t,
         igloo_RO_TYPEDECL_FREE(__free)
         );
 
-igloo_objecthandler_t * igloo_objecthandler_new(const igloo_objecthandler_ifdesc_t *ifdesc, igloo_ro_t backend_object, void *backend_userdata, const char *name, igloo_ro_t associated)
+igloo_objecthandler_t * igloo_objecthandler_new(const igloo_objecthandler_ifdesc_t *ifdesc, igloo_ro_t backend_object, void *backend_userdata, const char *name, igloo_ro_t associated, igloo_ro_t instance)
 {
-    igloo_objecthandler_t *handler = igloo_interface_base_new(igloo_objecthandler_t, ifdesc, backend_object, backend_userdata, name, associated);
+    igloo_objecthandler_t *handler = igloo_interface_base_new(igloo_objecthandler_t, ifdesc, backend_object, backend_userdata, name, associated, instance);
 
     if (!handler)
         return NULL;
diff --git a/src/private.h b/src/private.h
index 481a299..2751c23 100644
--- a/src/private.h
+++ b/src/private.h
@@ -56,8 +56,8 @@ void igloo_interface_base_free(igloo_ro_t self);
 #define igloo_INTERFACE_CAST(obj) ((igloo__interface_base_t*)igloo_RO__GETBASE(obj))
 #define igloo_INTERFACE_BASIC_CALL(obj) (obj), &(igloo_INTERFACE_CAST(obj)->backend_object), &(igloo_INTERFACE_CAST(obj)->backend_userdata)
 
-igloo_ro_t igloo_interface_base_new_real(const igloo_ro_type_t *type, size_t description_length, const igloo_interface_base_ifdesc_t *ifdesc, igloo_ro_t backend_object, void *backend_userdata, const char *name, igloo_ro_t associated);
-#define igloo_interface_base_new(type, ifdesc, backend_object, backend_userdata, name, associated) igloo_RO_TO_TYPE(igloo_interface_base_new_real(igloo_ro__type__ ## type, sizeof(*(ifdesc)), (const igloo_interface_base_ifdesc_t*)(ifdesc), (backend_object), (backend_userdata), (name), (associated)), type)
+igloo_ro_t igloo_interface_base_new_real(const igloo_ro_type_t *type, size_t description_length, const igloo_interface_base_ifdesc_t *ifdesc, igloo_ro_t backend_object, void *backend_userdata, const char *name, igloo_ro_t associated, igloo_ro_t instance);
+#define igloo_interface_base_new(type, ifdesc, backend_object, backend_userdata, name, associated, instance) igloo_RO_TO_TYPE(igloo_interface_base_new_real(igloo_ro__type__ ## type, sizeof(*(ifdesc)), (const igloo_interface_base_ifdesc_t*)(ifdesc), (backend_object), (backend_userdata), (name), (associated), (instance)), type)
 
 size_t igloo_private__vsnprintf_Hstrlen(const char *str, int is_alt, int allow_space);
 void igloo_private__vsnprintf(char *str, size_t size, const char *format, va_list ap);
diff --git a/src/ro.c b/src/ro.c
index ac8726b..b524ed1 100644
--- a/src/ro.c
+++ b/src/ro.c
@@ -68,8 +68,7 @@ igloo_ro_t      igloo_RO_TO_TYPE_raw(igloo_ro_t object, const igloo_ro_type_t *t
     return igloo_RO_IS_VALID_raw_li(object, type) ? object : igloo_RO_NULL;
 }
 
-
-igloo_ro_t      igloo_ro_new__raw(const igloo_ro_type_t *type, const char *name, igloo_ro_t associated)
+igloo_ro_t      igloo_ro_new__raw(const igloo_ro_type_t *type, const char *name, igloo_ro_t associated, igloo_ro_t instance)
 {
     igloo_ro_base_t *base;
 
@@ -102,10 +101,19 @@ igloo_ro_t      igloo_ro_new__raw(const igloo_ro_type_t *type, const char *name,
         base->associated = associated;
     }
 
+    if (!igloo_RO_IS_NULL(instance)) {
+        if (igloo_ro_ref(instance) != igloo_ERROR_NONE) {
+            igloo_ro_unref(base);
+            return igloo_RO_NULL;
+        }
+
+        base->instance = instance;
+    }
+
     return (igloo_ro_t)base;
 }
 
-igloo_ro_t      igloo_ro_new__simple(const igloo_ro_type_t *type, const char *name, igloo_ro_t associated, ...)
+igloo_ro_t      igloo_ro_new__simple(const igloo_ro_type_t *type, const char *name, igloo_ro_t associated, igloo_ro_t instance, ...)
 {
     igloo_ro_t ret;
     int res;
@@ -117,11 +125,11 @@ igloo_ro_t      igloo_ro_new__simple(const igloo_ro_type_t *type, const char *na
     if (!type->type_newcb)
         return igloo_RO_NULL;
 
-    ret = igloo_ro_new__raw(type, name, associated);
+    ret = igloo_ro_new__raw(type, name, associated, instance);
     if (igloo_RO_IS_NULL(ret))
         return igloo_RO_NULL;
 
-    va_start(ap, associated);
+    va_start(ap, instance);
     res = type->type_newcb(ret, type, ap);
     va_end(ap);
 
diff --git a/src/stdio.c b/src/stdio.c
index 27f9ced..c62fc0a 100644
--- a/src/stdio.c
+++ b/src/stdio.c
@@ -60,7 +60,7 @@ static const igloo_io_ifdesc_t igloo_stdio_ifdesc = {
     .get_fd_for_systemcall = __get_fd_for_systemcall
 };
 
-igloo_io_t * igloo_stdio_new_file(const char *filename, const char *mode, const char *name, igloo_ro_t associated)
+igloo_io_t * igloo_stdio_new_file(const char *filename, const char *mode, const char *name, igloo_ro_t associated, igloo_ro_t instance)
 {
     FILE *file = fopen(filename, mode);
     igloo_io_t *io;
@@ -68,7 +68,7 @@ igloo_io_t * igloo_stdio_new_file(const char *filename, const char *mode, const
     if (!file)
         return NULL;
 
-    io = igloo_io_new(&igloo_stdio_ifdesc, igloo_RO_NULL, file, name, associated);
+    io = igloo_io_new(&igloo_stdio_ifdesc, igloo_RO_NULL, file, name, associated, instance);
     if (!io) {
         fclose(file);
         return io;
diff --git a/src/tests/ctest_logmsg.c b/src/tests/ctest_logmsg.c
index 25fb7b8..02d44be 100644
--- a/src/tests/ctest_logmsg.c
+++ b/src/tests/ctest_logmsg.c
@@ -28,11 +28,11 @@ static void test_create_unref(void)
     ctest_test("logmsg created", !igloo_RO_IS_NULL(msg));
     ctest_test("un-referenced", igloo_ro_unref(msg) == igloo_ERROR_NONE);
 
-    formater = igloo_logmsg_formarter(igloo_RO_NULL, NULL, NULL, igloo_RO_NULL);
+    formater = igloo_logmsg_formarter(igloo_RO_NULL, NULL, NULL, igloo_RO_NULL, igloo_RO_NULL);
     ctest_test("formater created", !igloo_RO_IS_NULL(formater));
     ctest_test("un-referenced", igloo_ro_unref(formater) == igloo_ERROR_NONE);
 
-    filter = igloo_logmsg_filter(igloo_LOGLEVEL__NONE, igloo_LOGLEVEL__NONE, igloo_LOGMSG_OPT_NONE, igloo_LOGMSG_OPT_NONE, NULL, NULL, NULL, NULL, igloo_RO_NULL);
+    filter = igloo_logmsg_filter(igloo_LOGLEVEL__NONE, igloo_LOGLEVEL__NONE, igloo_LOGMSG_OPT_NONE, igloo_LOGMSG_OPT_NONE, NULL, NULL, NULL, NULL, igloo_RO_NULL, igloo_RO_NULL);
     ctest_test("filter created", !igloo_RO_IS_NULL(filter));
     ctest_test("un-referenced", igloo_ro_unref(filter) == igloo_ERROR_NONE);
 }
@@ -96,7 +96,7 @@ static void test_filter(void)
     igloo_logmsg_t *msg;
     igloo_ro_base_t *base;
 
-    filter = igloo_logmsg_filter(igloo_LOGLEVEL_ERROR, igloo_LOGLEVEL_WARN, igloo_LOGMSG_OPT_NONE, igloo_LOGMSG_OPT_NONE, NULL, NULL, NULL, NULL, igloo_RO_NULL);
+    filter = igloo_logmsg_filter(igloo_LOGLEVEL_ERROR, igloo_LOGLEVEL_WARN, igloo_LOGMSG_OPT_NONE, igloo_LOGMSG_OPT_NONE, NULL, NULL, NULL, NULL, igloo_RO_NULL, igloo_RO_NULL);
     ctest_test("filter created", !igloo_RO_IS_NULL(filter));
 
     base = igloo_ro_new(igloo_ro_base_t);