diff --git a/src/modules/module-client-node/client-node.c b/src/modules/module-client-node/client-node.c
index 6729acbc4..ac6b4cccc 100644
--- a/src/modules/module-client-node/client-node.c
+++ b/src/modules/module-client-node/client-node.c
@@ -1239,15 +1239,16 @@ static void node_free(void *data)
 static int port_init_mix(void *data, struct pw_port_mix *mix)
 {
 	struct impl *impl = data;
-	uint32_t ioid;
 
-	ioid = pw_map_insert_new(&impl->io_map, NULL);
+	mix->id = pw_map_insert_new(&impl->io_map, NULL);
 
-	mix->port.io = SPA_MEMBER(impl->io_areas->ptr, ioid * sizeof(struct spa_io_buffers), void);
+	mix->port.io = SPA_MEMBER(impl->io_areas->ptr,
+			mix->id * sizeof(struct spa_io_buffers), void);
 	mix->port.io->buffer_id = SPA_ID_INVALID;
 	mix->port.io->status = SPA_STATUS_NEED_BUFFER;
 
-	pw_log_debug("client-node %p: init mix io %d %p", impl, ioid, mix->port.io);
+	pw_log_debug("client-node %p: init mix io %d %p %p", impl, mix->id, mix->port.io,
+			impl->io_areas->ptr);
 
 	return 0;
 }
@@ -1255,11 +1256,11 @@ static int port_init_mix(void *data, struct pw_port_mix *mix)
 static int port_release_mix(void *data, struct pw_port_mix *mix)
 {
 	struct impl *impl = data;
-	uint32_t id;
 
-	id = (mix->port.io - (struct spa_io_buffers*)impl->io_areas->ptr);
+	pw_log_debug("client-node %p: remove mix io %d %p %p", impl, mix->id, mix->port.io,
+			impl->io_areas->ptr);
 
-	pw_map_remove(&impl->io_map, id);
+	pw_map_remove(&impl->io_map, mix->id);
 	return 0;
 }
 
diff --git a/src/pipewire/private.h b/src/pipewire/private.h
index f9864b07e..7de2a9a26 100644
--- a/src/pipewire/private.h
+++ b/src/pipewire/private.h
@@ -291,6 +291,7 @@ struct pw_port_mix {
 	struct spa_graph_port port;
 	struct spa_buffer **buffers;
 	uint32_t n_buffers;
+	uint32_t id;
 };
 
 struct pw_port_implementation {