diff --git a/notebooks/Jungfrau/Jungfrau_Gain_Correct_and_Verify_NBC.ipynb b/notebooks/Jungfrau/Jungfrau_Gain_Correct_and_Verify_NBC.ipynb
index ca2c87b3240b53b1f371421fbe2c26d430da8f35..80ee348612f97700881ea5b088ed7a3a61867faa 100644
--- a/notebooks/Jungfrau/Jungfrau_Gain_Correct_and_Verify_NBC.ipynb
+++ b/notebooks/Jungfrau/Jungfrau_Gain_Correct_and_Verify_NBC.ipynb
@@ -435,14 +435,16 @@
     "                    print(f'Data shape: {oshape}')\n",
     "                    if not oshape[0]:\n",
     "                        raise ValueError(f\"No image data: shape {oshape}\")\n",
+    "                    # Chunk always contains >= 1 complete image\n",
+    "                    chunk_shape = (chunk_size_idim, 1) + oshape[-2:]\n",
     "                    ddset = ofile.create_dataset(h5path_f+\"/adc\",\n",
     "                                                 oshape,\n",
-    "                                                 chunks=(chunk_size_idim, 1, oshape[1], oshape[2]),\n",
+    "                                                 chunks=chunk_shape,\n",
     "                                                 dtype=np.float32)\n",
     "\n",
     "                    mskset = ofile.create_dataset(h5path_f+\"/mask\",\n",
     "                                                  oshape,\n",
-    "                                                  chunks=(chunk_size_idim, 1, oshape[1], oshape[2]),\n",
+    "                                                  chunks=chunk_shape,\n",
     "                                                  dtype=np.uint32,\n",
     "                                                  compression=\"gzip\", compression_opts=1, shuffle=True)\n",
     "\n",