diff --git a/examples/notebooks/Upper_Air_BUFR_Soundings.ipynb b/examples/notebooks/Upper_Air_BUFR_Soundings.ipynb
index 6a4e89a..f535700 100644
--- a/examples/notebooks/Upper_Air_BUFR_Soundings.ipynb
+++ b/examples/notebooks/Upper_Air_BUFR_Soundings.ipynb
@@ -111,7 +111,7 @@
     "# assign units\n",
     "p = (prSig/100) * units.mbar\n",
     "wpres = (wpres/100) * units.mbar\n",
-    "u,v = wind_components(spd, np.deg2rad(direc))\n",
+    "u,v = wind_components(spd * units.knots, np.deg2rad(direc))\n",
     "\n",
     "if tpUnit is 'K':\n",
     "    T = (tpSig-273.15) * units.degC\n",