diff --git a/src/box/lua/slab.c b/src/box/lua/slab.c
index 57c7cb8817500c65a7cccccd77b25a7fcacaa15a..39cbe632f1a76c85d95ee4df920eb88adcff2b13 100644
--- a/src/box/lua/slab.c
+++ b/src/box/lua/slab.c
@@ -34,6 +34,7 @@
 #include <lua.h>
 #include <lauxlib.h>
 #include <lualib.h>
+#include <lj_obj.h> /* internals: lua in box.runtime.info() */
 
 #include "small/small.h"
 #include "small/quota.h"
@@ -208,6 +209,13 @@ lbox_runtime_info(struct lua_State *L)
 	luaL_pushuint64(L, quota_total(runtime.quota));
 	lua_settable(L, -3);
 
+	/*
+	 * Lua GC heap size
+	 */
+	lua_pushstring(L, "lua");
+	lua_pushinteger(L, G(L)->gc.total);
+	lua_settable(L, -3);
+
 	return 1;
 }