diff --git a/src/lua.rs b/src/lua.rs
index dd8b448..a768248 100644
--- a/src/lua.rs
+++ b/src/lua.rs
@@ -2402,6 +2402,7 @@ impl Lua {
 
         unsafe extern "C" fn unpack(state: *mut ffi::lua_State) -> c_int {
             let len = ffi::lua_tointeger(state, 2);
+            ffi::luaL_checkstack(state, len as c_int, ptr::null());
             for i in 1..=len {
                 ffi::lua_rawgeti(state, 1, i);
             }