diff --git a/doc/walkthrough/gre_walkthrough.ipynb b/doc/walkthrough/gre_walkthrough.ipynb
index 35e2060..4a591ae 100644
--- a/doc/walkthrough/gre_walkthrough.ipynb
+++ b/doc/walkthrough/gre_walkthrough.ipynb
@@ -1,6 +1,7 @@
 {
  "cells": [
   {
+   "attachments": {},
    "cell_type": "markdown",
    "metadata": {},
    "source": [
@@ -15,7 +16,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": null,
+   "execution_count": 2,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -28,11 +29,12 @@
     "from pypulseq.make_adc import make_adc\n",
     "from pypulseq.make_delay import make_delay\n",
     "from pypulseq.make_sinc_pulse import make_sinc_pulse\n",
-    "from pypulseq.make_trap_pulse import make_trapezoid\n",
+    "from pypulseq.make_trapezoid import make_trapezoid\n",
     "from pypulseq.opts import Opts"
    ]
   },
   {
+   "attachments": {},
    "cell_type": "markdown",
    "metadata": {},
    "source": [
@@ -41,7 +43,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": null,
+   "execution_count": 3,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -61,6 +63,7 @@
    ]
   },
   {
+   "attachments": {},
    "cell_type": "markdown",
    "metadata": {},
    "source": [
@@ -69,12 +72,24 @@
   },
   {
    "cell_type": "code",
-   "execution_count": null,
+   "execution_count": 4,
    "metadata": {},
-   "outputs": [],
+   "outputs": [
+    {
+     "ename": "TypeError",
+     "evalue": "cannot unpack non-iterable types.SimpleNamespace object",
+     "output_type": "error",
+     "traceback": [
+      "\u001b[0;31m---------------------------------------------------------------------------\u001b[0m",
+      "\u001b[0;31mTypeError\u001b[0m                                 Traceback (most recent call last)",
+      "\u001b[1;32m/Users/bilal/workspace/pypulseq_bilal/doc/walkthrough/gre_walkthrough.ipynb Cell 6\u001b[0m in \u001b[0;36m<cell line: 1>\u001b[0;34m()\u001b[0m\n\u001b[0;32m----> <a href='vscode-notebook-cell:/Users/bilal/workspace/pypulseq_bilal/doc/walkthrough/gre_walkthrough.ipynb#W5sZmlsZQ%3D%3D?line=0'>1</a>\u001b[0m rf, gz, gzr \u001b[39m=\u001b[39m make_sinc_pulse(flip_angle\u001b[39m=\u001b[39malpha \u001b[39m*\u001b[39m math\u001b[39m.\u001b[39mpi \u001b[39m/\u001b[39m \u001b[39m180\u001b[39m, duration\u001b[39m=\u001b[39m\u001b[39m4e-3\u001b[39m, slice_thickness\u001b[39m=\u001b[39mslice_thickness,\n\u001b[1;32m      <a href='vscode-notebook-cell:/Users/bilal/workspace/pypulseq_bilal/doc/walkthrough/gre_walkthrough.ipynb#W5sZmlsZQ%3D%3D?line=1'>2</a>\u001b[0m                               apodization\u001b[39m=\u001b[39m\u001b[39m0.5\u001b[39m, time_bw_product\u001b[39m=\u001b[39m\u001b[39m4\u001b[39m, system\u001b[39m=\u001b[39msys)\n\u001b[1;32m      <a href='vscode-notebook-cell:/Users/bilal/workspace/pypulseq_bilal/doc/walkthrough/gre_walkthrough.ipynb#W5sZmlsZQ%3D%3D?line=3'>4</a>\u001b[0m delta_k \u001b[39m=\u001b[39m \u001b[39m1\u001b[39m \u001b[39m/\u001b[39m fov\n\u001b[1;32m      <a href='vscode-notebook-cell:/Users/bilal/workspace/pypulseq_bilal/doc/walkthrough/gre_walkthrough.ipynb#W5sZmlsZQ%3D%3D?line=4'>5</a>\u001b[0m gx \u001b[39m=\u001b[39m make_trapezoid(channel\u001b[39m=\u001b[39m\u001b[39m'\u001b[39m\u001b[39mx\u001b[39m\u001b[39m'\u001b[39m, flat_area\u001b[39m=\u001b[39mNx \u001b[39m*\u001b[39m delta_k, flat_time\u001b[39m=\u001b[39m\u001b[39m6.4e-3\u001b[39m, system\u001b[39m=\u001b[39msys)\n",
+      "\u001b[0;31mTypeError\u001b[0m: cannot unpack non-iterable types.SimpleNamespace object"
+     ]
+    }
+   ],
    "source": [
     "rf, gz, gzr = make_sinc_pulse(flip_angle=alpha * math.pi / 180, duration=4e-3, slice_thickness=slice_thickness,\n",
-    "                              apodization=0.5, time_bw_product=4, system=sys)\n",
+    "                              apodization=0.5, time_bw_product=4, system=sys, return_gz=True)\n",
     "\n",
     "delta_k = 1 / fov\n",
     "gx = make_trapezoid(channel='x', flat_area=Nx * delta_k, flat_time=6.4e-3, system=sys)\n",
@@ -95,6 +110,7 @@
    ]
   },
   {
+   "attachments": {},
    "cell_type": "markdown",
    "metadata": {},
    "source": [
@@ -128,6 +144,7 @@
    ]
   },
   {
+   "attachments": {},
    "cell_type": "markdown",
    "metadata": {},
    "source": [
@@ -147,6 +164,7 @@
    ]
   },
   {
+   "attachments": {},
    "cell_type": "markdown",
    "metadata": {},
    "source": [
@@ -180,7 +198,7 @@
    "name": "python",
    "nbconvert_exporter": "python",
    "pygments_lexer": "ipython3",
-   "version": "3.6.3"
+   "version": "3.10.4"
   }
  },
  "nbformat": 4,