diff --git a/kiwmi/luak.c b/kiwmi/luak.c
index f2971ef..6a84e61 100644
--- a/kiwmi/luak.c
+++ b/kiwmi/luak.c
@@ -37,6 +37,8 @@ l_lua_callback_cancel(lua_State *L)
     wl_list_remove(&lc->listener.link);
     wl_list_remove(&lc->link);
 
+    luaL_unref(L, LUA_REGISTRYINDEX, lc->callback_ref);
+
     free(lc);
 
     return 0;
@@ -300,6 +302,8 @@ luaK_fini(struct kiwmi_lua *lua)
         wl_list_remove(&lc->listener.link);
         wl_list_remove(&lc->link);
 
+        luaL_unref(lua->L, LUA_REGISTRYINDEX, lc->callback_ref);
+
         free(lc);
     }