diff --git a/todonotes.dtx b/todonotes.dtx
index c4bd1e8..44bd05b 100644
--- a/todonotes.dtx
+++ b/todonotes.dtx
@@ -1218,7 +1218,7 @@
 \newcommand{\phantomsection}{}
 \fi
 \ifdim \marginparwidth < 2cm
-\todo[inline]{Warning. The length $\backslash$marginparwidth is
+\PackageWarning{todonotes}{The length $\backslash$marginparwidth is
 less than 2cm and will most likely cause issues with the
 appearance of inserted todonotes.
 The issue can be solved by adding a line like