diff --git a/book/content/modelling/06_heat_transfer/03_validation_example.ipynb b/book/content/modelling/06_heat_transfer/03_validation_example.ipynb
index 08a3ac87..80eb4c32 100644
--- a/book/content/modelling/06_heat_transfer/03_validation_example.ipynb
+++ b/book/content/modelling/06_heat_transfer/03_validation_example.ipynb
@@ -272,7 +272,7 @@
    },
    "outputs": [],
    "source": [
-    "'for device on the ceiling'\n",
+    "'for device on the front wall'\n",
     "\n",
     "def heat_flux(x,y):\n",
     "    \n",