diff --git a/examples/notebooks/Upper_Air_BUFR_Soundings.ipynb b/examples/notebooks/Upper_Air_BUFR_Soundings.ipynb
index f535700..febb754 100644
--- a/examples/notebooks/Upper_Air_BUFR_Soundings.ipynb
+++ b/examples/notebooks/Upper_Air_BUFR_Soundings.ipynb
@@ -113,7 +113,7 @@
     "wpres = (wpres/100) * units.mbar\n",
     "u,v = wind_components(spd * units.knots, np.deg2rad(direc))\n",
     "\n",
-    "if tpUnit is 'K':\n",
+    "if tpUnit == 'K':\n",
     "    T = (tpSig-273.15) * units.degC\n",
     "    Td = (tdSig-273.15) * units.degC\n",
     "    tman = tman * units.degC\n",