diff --git a/src/context.c b/src/context.c
index 61291768..50ee71c3 100644
--- a/src/context.c
+++ b/src/context.c
@@ -239,34 +239,40 @@ transaction_id_cmp(const void *id1, const void *id2)
  * Call this to initialize the context that is used in other getdns calls.
  */
 getdns_return_t
-getdns_context_create_with_memory_functions(struct getdns_context ** context,
+getdns_context_create_with_extended_memory_functions(
+    struct getdns_context ** context,
     int set_from_os,
-    void *(*malloc)(size_t),
-    void *(*realloc)(void *, size_t),
-    void (*free)(void *)
+    void *userarg,
+    void *(*malloc)(void *userarg, size_t),
+    void *(*realloc)(void *userarg, void *, size_t),
+    void (*free)(void *userarg, void *)
     )
 {
 	struct getdns_context *result = NULL;
+	mf_union mf;
 
 	if (!context || !malloc || !realloc || !free)
 		return GETDNS_RETURN_GENERIC_ERROR;
 
     /** default init **/
-	result = (*malloc)(sizeof(struct getdns_context));
+	mf.ext.malloc = malloc;
+	result = userarg == MF_PLAIN
+	       ? (*mf.pln.malloc)(         sizeof(struct getdns_context))
+	       : (*mf.ext.malloc)(userarg, sizeof(struct getdns_context));
 	if (!result) {
 		return GETDNS_RETURN_GENERIC_ERROR;
 	}
-	result->my_mf.mf_arg         = MF_PLAIN;
-	result->my_mf.mf.pln.malloc  = malloc;
-	result->my_mf.mf.pln.realloc = realloc;
-	result->my_mf.mf.pln.free    = free;
+	result->my_mf.mf_arg         = userarg;
+	result->my_mf.mf.ext.malloc  = malloc;
+	result->my_mf.mf.ext.realloc = realloc;
+	result->my_mf.mf.ext.free    = free;
 
 	result->update_callback = NULL;
 
-	result->mf.mf_arg          = MF_PLAIN;
-	result->mf.mf.pln.malloc   = malloc;
-	result->mf.mf.pln.realloc  = realloc;
-	result->mf.mf.pln.free     = free;
+	result->mf.mf_arg          = userarg;
+	result->mf.mf.ext.malloc   = malloc;
+	result->mf.mf.ext.realloc  = realloc;
+	result->mf.mf.ext.free     = free;
 
 	result->event_base_sync = event_base_new();
 	result->unbound_sync = ub_ctx_create_event(result->event_base_sync);
@@ -312,6 +318,28 @@ getdns_context_create_with_memory_functions(struct getdns_context ** context,
 	return GETDNS_RETURN_GOOD;
 }				/* getdns_context_create */
 
+/*
+ * getdns_context_create
+ *
+ * Call this to initialize the context that is used in other getdns calls.
+ */
+getdns_return_t
+getdns_context_create_with_memory_functions(struct getdns_context ** context,
+    int set_from_os,
+    void *(*malloc)(size_t),
+    void *(*realloc)(void *, size_t),
+    void (*free)(void *)
+    )
+{
+	mf_union mf;
+	mf.pln.malloc = malloc;
+	mf.pln.realloc = realloc;
+	mf.pln.free = free;
+	return getdns_context_create_with_extended_memory_functions(
+	    context, set_from_os, MF_PLAIN,
+	    mf.ext.malloc, mf.ext.realloc, mf.ext.free);
+}				/* getdns_context_create */
+
 /*
  * getdns_context_create
  *
@@ -791,6 +819,36 @@ getdns_context_set_edns_do_bit(struct getdns_context *context, uint8_t value)
 	return GETDNS_RETURN_GOOD;
 }				/* getdns_context_set_edns_do_bit */
 
+/*
+ * getdns_context_set_extended_memory_functions
+ *
+ */
+getdns_return_t
+getdns_context_set_extended_memory_functions(
+    struct getdns_context *context,
+    void *userarg,
+    void *(*malloc) (void *userarg, size_t),
+    void *(*realloc) (void *userarg, void *, size_t),
+    void (*free) (void *userarg, void *)
+    )
+{
+	if (!context)
+		return GETDNS_RETURN_BAD_CONTEXT;
+
+	if (!malloc || !realloc || !free)
+		return GETDNS_RETURN_CONTEXT_UPDATE_FAIL;
+
+	context->mf.mf_arg         = userarg;
+	context->mf.mf.ext.malloc  = malloc;
+	context->mf.mf.ext.realloc = realloc;
+	context->mf.mf.ext.free    = free;
+
+	dispatch_updated(context, GETDNS_CONTEXT_CODE_MEMORY_FUNCTIONS);
+
+	return GETDNS_RETURN_GOOD;
+} /* getdns_context_set_extended_memory_functions*/
+
+
 /*
  * getdns_context_set_memory_functions
  *
@@ -802,20 +860,12 @@ getdns_context_set_memory_functions(struct getdns_context *context,
     void (*free) (void *)
     )
 {
-	if (!context)
-		return GETDNS_RETURN_BAD_CONTEXT;
-
-	if (!malloc || !realloc || !free)
-		return GETDNS_RETURN_CONTEXT_UPDATE_FAIL;
-
-	context->mf.mf_arg         = MF_PLAIN;
-	context->mf.mf.pln.malloc  = malloc;
-	context->mf.mf.pln.realloc = realloc;
-	context->mf.mf.pln.free    = free;
-
-	dispatch_updated(context, GETDNS_CONTEXT_CODE_MEMORY_FUNCTIONS);
-
-	return GETDNS_RETURN_GOOD;
+	mf_union mf;
+	mf.pln.malloc = malloc;
+	mf.pln.realloc = realloc;
+	mf.pln.free = free;
+	return getdns_context_set_extended_memory_functions(
+	    context, MF_PLAIN, mf.ext.malloc, mf.ext.realloc, mf.ext.free);
 } /* getdns_context_set_memory_functions*/
 
 
diff --git a/src/dict.c b/src/dict.c
index ed414167..96523a73 100644
--- a/src/dict.c
+++ b/src/dict.c
@@ -83,8 +83,9 @@ getdns_dict_get_names(struct getdns_dict * dict, struct getdns_list ** answer)
 	if (!dict || !answer)
 		return GETDNS_RETURN_NO_SUCH_DICT_NAME;
 
-	*answer = getdns_list_create_with_memory_functions(
-	    dict->mf.mf.pln.malloc, dict->mf.mf.pln.realloc, dict->mf.mf.pln.free);
+	*answer = getdns_list_create_with_extended_memory_functions(
+	    dict->mf.mf_arg, dict->mf.mf.ext.malloc,
+	    dict->mf.mf.ext.realloc, dict->mf.mf.ext.free);
 	if (!*answer)
 		return GETDNS_RETURN_NO_SUCH_DICT_NAME;
 
@@ -188,37 +189,57 @@ getdns_dict_get_int(struct getdns_dict * dict, char *name, uint32_t * answer)
 }				/* getdns_dict_get_int */
 
 struct getdns_dict *
-getdns_dict_create_with_memory_functions(void *(*malloc)(size_t),
-    void *(*realloc)(void *, size_t), void (*free)(void *))
+getdns_dict_create_with_extended_memory_functions(
+    void *userarg,
+    void *(*malloc)(void *userarg, size_t),
+    void *(*realloc)(void *userarg, void *, size_t),
+    void (*free)(void *userarg, void *))
 {
 	struct getdns_dict *dict;
+	mf_union mf;
 
 	if (!malloc || !realloc || !free)
 		return NULL;
 
-	dict = (struct getdns_dict *)(*malloc)(sizeof(struct getdns_dict));
+	mf.ext.malloc = malloc;
+	dict = userarg == MF_PLAIN
+	     ? (struct getdns_dict*)(*mf.pln.malloc)(
+	           sizeof(struct getdns_dict))
+	     : (struct getdns_dict*)(*mf.ext.malloc)(userarg,
+	           sizeof(struct getdns_dict));
 	if (!dict)
 		return NULL;
 
-	dict->mf.mf_arg         = MF_PLAIN;
-	dict->mf.mf.pln.malloc  = malloc;
-	dict->mf.mf.pln.realloc = realloc;
-	dict->mf.mf.pln.free    = free;
+	dict->mf.mf_arg         = userarg;
+	dict->mf.mf.ext.malloc  = malloc;
+	dict->mf.mf.ext.realloc = realloc;
+	dict->mf.mf.ext.free    = free;
 
 	ldns_rbtree_init(&(dict->root),
 	    (int (*)(const void *, const void *)) strcmp);
 	return dict;
 }
 
+struct getdns_dict *
+getdns_dict_create_with_memory_functions(void *(*malloc)(size_t),
+    void *(*realloc)(void *, size_t), void (*free)(void *))
+{
+	mf_union mf;
+	mf.pln.malloc = malloc;
+	mf.pln.realloc = realloc;
+	mf.pln.free = free;
+	return getdns_dict_create_with_extended_memory_functions(
+	    MF_PLAIN, mf.ext.malloc, mf.ext.realloc, mf.ext.free);
+}
 
 /*-------------------------- getdns_dict_create_with_context */
 struct getdns_dict *
 getdns_dict_create_with_context(struct getdns_context *context)
 {
 	if (context)
-		return getdns_dict_create_with_memory_functions(
-		    context->mf.mf.pln.malloc,
-		    context->mf.mf.pln.realloc, context->mf.mf.pln.free);
+		return getdns_dict_create_with_extended_memory_functions(
+		    context->mf.mf_arg, context->mf.mf.ext.malloc,
+		    context->mf.mf.ext.realloc, context->mf.mf.ext.free);
 	else
 		return getdns_dict_create_with_memory_functions(&malloc,
 		    &realloc, &free);
@@ -254,10 +275,11 @@ getdns_dict_copy(struct getdns_dict * srcdict, struct getdns_dict ** dstdict)
 		*dstdict = NULL;
 		return GETDNS_RETURN_GOOD;
 	}
-	*dstdict = getdns_dict_create_with_memory_functions(
-	    srcdict->mf.mf.pln.malloc,
-	    srcdict->mf.mf.pln.realloc,
-	    srcdict->mf.mf.pln.free);
+	*dstdict = getdns_dict_create_with_extended_memory_functions(
+	    srcdict->mf.mf_arg,
+	    srcdict->mf.mf.ext.malloc,
+	    srcdict->mf.mf.ext.realloc,
+	    srcdict->mf.mf.ext.free);
 	if (!*dstdict)
 		return GETDNS_RETURN_NO_SUCH_DICT_NAME;
 
diff --git a/src/list.c b/src/list.c
index ec81d7d9..14a9d8cf 100644
--- a/src/list.c
+++ b/src/list.c
@@ -164,10 +164,11 @@ getdns_list_copy(struct getdns_list * srclist, struct getdns_list ** dstlist)
 		*dstlist = NULL;
 		return GETDNS_RETURN_GOOD;
 	}
-	*dstlist = getdns_list_create_with_memory_functions(
-	    srclist->mf.mf.pln.malloc,
-	    srclist->mf.mf.pln.realloc,
-	    srclist->mf.mf.pln.free
+	*dstlist = getdns_list_create_with_extended_memory_functions(
+	    srclist->mf.mf_arg,
+	    srclist->mf.mf.ext.malloc,
+	    srclist->mf.mf.ext.realloc,
+	    srclist->mf.mf.ext.free
 	);
 	if (!dstlist)
 		return GETDNS_RETURN_NO_SUCH_LIST_ITEM;
@@ -210,22 +211,31 @@ getdns_list_copy(struct getdns_list * srclist, struct getdns_list ** dstlist)
 }				/* getdns_list_copy */
 
 struct getdns_list *
-getdns_list_create_with_memory_functions(void *(*malloc)(size_t),
-    void *(*realloc)(void *, size_t), void (*free)(void *))
+getdns_list_create_with_extended_memory_functions(
+    void *userarg,
+    void *(*malloc)(void *userarg, size_t),
+    void *(*realloc)(void *userarg, void *, size_t),
+    void (*free)(void *userarg, void *))
 {
 	struct getdns_list *list;
+	mf_union mf;
 
 	if (!malloc || !realloc || !free)
 		return NULL;
 
-	list = (struct getdns_list *)(*malloc)(sizeof(struct getdns_list));
+	mf.ext.malloc = malloc;
+	list = userarg == MF_PLAIN
+	     ? (struct getdns_list *)(*mf.pln.malloc)(
+	           sizeof(struct getdns_list))
+	     : (struct getdns_list *)(*mf.ext.malloc)(userarg,
+	           sizeof(struct getdns_list));
 	if (!list)
 		return NULL;
 	
-	list->mf.mf_arg         = MF_PLAIN;
-	list->mf.mf.pln.malloc  = malloc;
-	list->mf.mf.pln.realloc = realloc;
-	list->mf.mf.pln.free    = free;
+	list->mf.mf_arg         = userarg;
+	list->mf.mf.ext.malloc  = malloc;
+	list->mf.mf.ext.realloc = realloc;
+	list->mf.mf.ext.free    = free;
 
 	list->numalloc = 0;
 	list->numinuse = 0;
@@ -237,15 +247,29 @@ getdns_list_create_with_memory_functions(void *(*malloc)(size_t),
 	return list;
 }
 
+struct getdns_list *
+getdns_list_create_with_memory_functions(void *(*malloc)(size_t),
+    void *(*realloc)(void *, size_t), void (*free)(void *))
+{
+	mf_union mf;
+	mf.pln.malloc = malloc;
+	mf.pln.realloc = realloc;
+	mf.pln.free = free;
+	return getdns_list_create_with_extended_memory_functions(
+	    MF_PLAIN, mf.ext.malloc, mf.ext.realloc, mf.ext.free);
+}
+
+
 /*-------------------------- getdns_list_create_with_context */
 struct getdns_list *
 getdns_list_create_with_context(struct getdns_context *context)
 {
 	if (context)
-		return getdns_list_create_with_memory_functions(
-		    context->mf.mf.pln.malloc,
-		    context->mf.mf.pln.realloc,
-		    context->mf.mf.pln.free
+		return getdns_list_create_with_extended_memory_functions(
+		    context->mf.mf_arg,
+		    context->mf.mf.ext.malloc,
+		    context->mf.mf.ext.realloc,
+		    context->mf.mf.ext.free
 		);
 	else
 		return getdns_list_create_with_memory_functions(malloc,
diff --git a/src/types-internal.h b/src/types-internal.h
index 73c21cd2..ecb22a61 100644
--- a/src/types-internal.h
+++ b/src/types-internal.h
@@ -179,9 +179,7 @@ typedef struct getdns_dns_req
 #define MF_PLAIN ((void *)&plain_mem_funcs_user_arg)
 extern void *plain_mem_funcs_user_arg;
 
-struct mem_funcs {
-	void *mf_arg;
-	union {
+typedef union {
 		struct {
 			void *(*malloc)(size_t);
 			void *(*realloc)(void *, size_t);
@@ -192,7 +190,11 @@ struct mem_funcs {
 			void *(*realloc)(void *userarg, void *, size_t);
 			void (*free)(void *userarg, void *);
 		} ext;
-	} mf;
+	} mf_union;
+
+struct mem_funcs {
+	void *mf_arg;
+	mf_union mf;
 };
 
 #define GETDNS_XMALLOC(obj, type, count)	\