diff --git a/examples/understanding_variograms_and_realizations.ipynb b/examples/understanding_variograms_and_realizations.ipynb
index 8badcbb..f033c0d 100644
--- a/examples/understanding_variograms_and_realizations.ipynb
+++ b/examples/understanding_variograms_and_realizations.ipynb
@@ -102,7 +102,8 @@
     "    axes.set_xlabel(\"column\")\n",
     "    axes.set_ylabel(\"row\")\n",
     "    axes.set_title(\"a random realization of HK\", loc=\"left\")\n",
-    "    plt.show()"
+    "    plt.show()\n",
+    "    del cb"
    ]
   },
   {