diff --git a/forgebox/__init__.py b/forgebox/__init__.py
index a070a77..3926618 100644
--- a/forgebox/__init__.py
+++ b/forgebox/__init__.py
@@ -1 +1 @@
-__version__ = "0.4.18.2"
+__version__ = "0.4.18.3"
diff --git a/forgebox/multiproc.py b/forgebox/multiproc.py
index ae64d6d..e48b74a 100644
--- a/forgebox/multiproc.py
+++ b/forgebox/multiproc.py
@@ -131,7 +131,7 @@ def __iter__(self):
 
     def __getitem__(self, idx):
         global DataFrameRowling_df
-        return DataFrameRowling_df[DataFrameRowling_df.index[idx]]
+        return DataFrameRowling_df[list(DataFrameRowling_df.index[idx]]
 
     def __next__(self):
         global DataFrameRowling_df
diff --git a/nbs/09_multiprocess.ipynb b/nbs/09_multiprocess.ipynb
index 49ebc19..117a37a 100644
--- a/nbs/09_multiprocess.ipynb
+++ b/nbs/09_multiprocess.ipynb
@@ -173,7 +173,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 59,
+   "execution_count": 60,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -204,7 +204,7 @@
     "            \n",
     "    def __getitem__(self, idx):\n",
     "        global DataFrameRowling_df\n",
-    "        return DataFrameRowling_df[DataFrameRowling_df.index[idx]]\n",
+    "        return DataFrameRowling_df[list(DataFrameRowling_df.index)[idx]]\n",
     "            \n",
     "    def __next__(self):\n",
     "        global DataFrameRowling_df\n",
@@ -216,7 +216,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 56,
+   "execution_count": 61,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -226,13 +226,34 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 57,
+   "execution_count": 62,
    "metadata": {},
    "outputs": [],
    "source": [
     "res = Parallel(backend=\"multiprocessing\", n_jobs=6)(delayed(get_line)(i) for i in DataFrameRowling(df))"
    ]
   },
+  {
+   "cell_type": "code",
+   "execution_count": 63,
+   "metadata": {},
+   "outputs": [
+    {
+     "data": {
+      "text/plain": [
+       "col1    5\n",
+       "Name: 5, dtype: int64"
+      ]
+     },
+     "execution_count": 63,
+     "metadata": {},
+     "output_type": "execute_result"
+    }
+   ],
+   "source": [
+    "res[5]"
+   ]
+  },
   {
    "cell_type": "code",
    "execution_count": null,
diff --git a/settings.ini b/settings.ini
index 3baed78..123762d 100644
--- a/settings.ini
+++ b/settings.ini
@@ -7,7 +7,7 @@ author = xiaochen(ray) zhang
 author_email = b2ray2c@gmail.com
 copyright = xiaochen(ray) zhang
 branch = master
-version = 0.4.18.2
+version = 0.4.18.3
 min_python = 3.6
 audience = Developers
 language = English