diff --git a/include/common.h b/include/common.h
index ee7f68b..a3a1dbf 100644
--- a/include/common.h
+++ b/include/common.h
@@ -57,6 +57,7 @@ struct nvnc_display;
 
 struct nvnc_common {
 	void* userdata;
+	nvnc_cleanup_fn cleanup_fn;
 };
 
 struct cut_text {
diff --git a/include/neatvnc.h b/include/neatvnc.h
index 6d1e2ab..64e7115 100644
--- a/include/neatvnc.h
+++ b/include/neatvnc.h
@@ -51,6 +51,7 @@ typedef bool (*nvnc_auth_fn)(const char* username, const char* password,
                              void* userdata);
 typedef void (*nvnc_cut_text_fn)(struct nvnc*, const char* text, uint32_t len);
 typedef void (*nvnc_fb_release_fn)(struct nvnc_fb*, void* context);
+typedef void (*nvnc_cleanup_fn)(void* userdata);
 
 extern const char nvnc_version[];
 
@@ -61,7 +62,7 @@ void nvnc_close(struct nvnc* self);
 void nvnc_add_display(struct nvnc*, struct nvnc_display*);
 void nvnc_remove_display(struct nvnc*, struct nvnc_display*);
 
-void nvnc_set_userdata(void* self, void* userdata);
+void nvnc_set_userdata(void* self, void* userdata, nvnc_cleanup_fn);
 void* nvnc_get_userdata(const void* self);
 
 struct nvnc* nvnc_client_get_server(const struct nvnc_client* client);
diff --git a/src/fb.c b/src/fb.c
index b27b681..08dca95 100644
--- a/src/fb.c
+++ b/src/fb.c
@@ -94,6 +94,10 @@ uint32_t nvnc_fb_get_fourcc_format(const struct nvnc_fb* fb)
 
 static void nvnc__fb_free(struct nvnc_fb* fb)
 {
+	nvnc_cleanup_fn cleanup = fb->common.cleanup_fn;
+	if (cleanup)
+		cleanup(fb->common.userdata);
+
 	free(fb->addr);
 	free(fb);
 }
diff --git a/src/server.c b/src/server.c
index 3ff5327..1eaefb1 100644
--- a/src/server.c
+++ b/src/server.c
@@ -99,6 +99,10 @@ static void client_close(struct nvnc_client* client)
 {
 	log_debug("client_close(%p): ref %d\n", client, client->ref);
 
+	nvnc_cleanup_fn cleanup = client->common.cleanup_fn;
+	if (cleanup)
+		cleanup(client->common.userdata);
+
 	nvnc_client_fn fn = client->cleanup_fn;
 	if (fn)
 		fn(client);
@@ -1177,6 +1181,10 @@ void nvnc_close(struct nvnc* self)
 {
 	struct nvnc_client* client;
 
+	nvnc_cleanup_fn cleanup = self->common.cleanup_fn;
+	if (cleanup)
+		cleanup(self->common.userdata);
+
 	if (self->display)
 		nvnc_display_unref(self->display);
 
@@ -1441,10 +1449,11 @@ void nvnc__damage_region(struct nvnc* self, const struct pixman_region16* damage
 }
 
 EXPORT
-void nvnc_set_userdata(void* self, void* userdata)
+void nvnc_set_userdata(void* self, void* userdata, nvnc_cleanup_fn cleanup_fn)
 {
 	struct nvnc_common* common = self;
 	common->userdata = userdata;
+	common->cleanup_fn = cleanup_fn;
 }
 
 EXPORT