diff --git a/todonotes.dtx b/todonotes.dtx
index 31d5cbe..cbe0e75 100644
--- a/todonotes.dtx
+++ b/todonotes.dtx
@@ -357,7 +357,7 @@
 % These options sets the default colors for the todo command.
 % There are four colors that can be specified. The border color
 % (default |bordercolor=black|) around the inserted text, the color
-% behind the inserted text (default |backgroundcolor=orange|), the 
+% behind the inserted text (default |backgroundcolor=orange|), the
 % color of the inserted text (default |textcolor=black|) and
 % the color of the line connecting the inserted textbox with the
 % current location in the text (default |linecolor=orange|).
@@ -1427,12 +1427,10 @@ prior to loading the todonotes package.} \else\fi%
 \define@key{todonotes.sty}%
     {textwidth}{\renewcommand{\@todonotes@textwidth}{#1}}
 %    \end{macrocode}
-% Make the text size as an option. It requires some magic with the
-% |\csname| and |\endcsname| macros, as commands cannot be taken as
-% options for a package.
+% Make the text size as an option.
 %    \begin{macrocode}
 \define@key{todonotes.sty}%
-    {textsize}{\renewcommand{\@todonotes@textsize}{\csname #1\endcsname}}
+    {textsize}{\renewcommand{\@todonotes@textsize}{#1}}
 %    \end{macrocode}
 % Add option for shadows behind the inserted notes
 %    \begin{macrocode}
@@ -1509,7 +1507,8 @@ prior to loading the todonotes package.} \else\fi%
 % Set a relative font size
 %    \begin{macrocode}
 \newcommand{\@todonotes@sizecommand}{}%
-\define@key{todonotes}{size}{\renewcommand{\@todonotes@sizecommand}{#1}}%
+\define@key{todonotes}{size}{\renewcommand{\@todonotes@sizecommand}{#1}%
+}%
 %    \end{macrocode}
 % Should the todo item be disabled?
 %    \begin{macrocode}
@@ -1774,6 +1773,18 @@ prior to loading the todonotes package.} \else\fi%
 %    \end{macrocode}
 % \end{macro}
 % \begin{macro}{drawInlineNote}
+% Define helper function |useSizeCommand|.
+%    \begin{macrocode}
+\newcommand{\@todonotes@useSizeCommand}{%
+\ifcsname \expandafter\string\@todonotes@sizecommand\endcsname
+\csname \expandafter\string\@todonotes@sizecommand\endcsname%
+\else
+\@todonotes@sizecommand
+\fi%
+}%
+%    \end{macrocode}
+% \end{macro}
+% \begin{macro}{drawInlineNote}
 % Define helper function |drawInlineNote|.
 %    \begin{macrocode}
 \newcommand{\@todonotes@drawInlineNote}{%
@@ -1784,9 +1795,9 @@ prior to loading the todonotes package.} \else\fi%
          \end{tikzpicture}%
          \if@todonotes@inlinepar\par\fi}%
             \if@todonotes@authorgiven%
-                {\noindent \@todonotes@sizecommand \@todonotes@author:\,\@todonotes@text}%
+                {\noindent \@todonotes@useSizeCommand \@todonotes@author:\,\@todonotes@text}%
             \else%
-                {\noindent \@todonotes@sizecommand \@todonotes@text}%
+                {\noindent \@todonotes@useSizeCommand \@todonotes@text}%
             \fi
         {\if@todonotes@inlinepar\par\noindent\fi%
          \begin{tikzpicture}[remember picture]%
@@ -1796,11 +1807,11 @@ prior to loading the todonotes package.} \else\fi%
     \else%
         {\if@todonotes@inlinepar\par\noindent\fi%
          \begin{tikzpicture}[remember picture]%
-            \draw node[inlinenotestyle,font=\@todonotes@sizecommand]{%
+            \draw node[inlinenotestyle,font=\@todonotes@useSizeCommand]{%
                 \if@todonotes@authorgiven%
-                    {\noindent \@todonotes@sizecommand \@todonotes@author:\,\@todonotes@text}%
+                    {\noindent \@todonotes@author:\,\@todonotes@text}%
                 \else%
-                    {\noindent \@todonotes@sizecommand \@todonotes@text}%
+                    {\noindent \@todonotes@text}%
                 \fi};%
          \end{tikzpicture}%
          \if@todonotes@inlinepar\par\fi}%
@@ -1817,9 +1828,9 @@ prior to loading the todonotes package.} \else\fi%
     \end{tikzpicture}\\%
     \begin{minipage}{\@todonotes@textwidth}%
     \if@todonotes@authorgiven%
-      \@todonotes@sizecommand \@todonotes@author \@todonotes@text%
+      \@todonotes@useSizeCommand \@todonotes@author \@todonotes@text%
     \else%
-      \@todonotes@sizecommand \@todonotes@text%
+      \@todonotes@useSizeCommand \@todonotes@text%
     \fi%
     \end{minipage}\\%
     \begin{tikzpicture}[remember picture]%
@@ -1829,15 +1840,15 @@ prior to loading the todonotes package.} \else\fi%
     \let\originalHbadness\hbadness%
     \hbadness 100000%
     \begin{tikzpicture}[remember picture,baseline=(X.base)]%
-        \node(X){\vphantom{\@todonotes@sizecommand X}};%
+        \node(X){\vphantom{\@todonotes@useSizeCommand X}};%
         \if@todonotes@authorgiven%
-            \draw node[notestyle,font=\@todonotes@sizecommand,anchor=north] (inNote) at (X.north)%
-                {\@todonotes@sizecommand\@todonotes@author};%
+            \draw node[notestyle,font=\@todonotes@useSizeCommand,anchor=north] (inNote) at (X.north)%
+                {\@todonotes@author};%
             \node(Y)[below=of X]{};%
-            \draw node[notestyle,font=\@todonotes@sizecommand,anchor=north] (inNote) at (X.south)%
+            \draw node[notestyle,font=\@todonotes@useSizeCommand,anchor=north] (inNote) at (X.south)%
                 {\@todonotes@text};%
         \else%
-            \draw node[notestyle,font=\@todonotes@sizecommand,anchor=north] (inNote) at (X.north)%
+            \draw node[notestyle,font=\@todonotes@useSizeCommand,anchor=north] (inNote) at (X.north)%
                 {\@todonotes@text};%
         \fi%
     \end{tikzpicture}%
@@ -1913,7 +1924,7 @@ prior to loading the todonotes package.} \else\fi%
     (-2, -0.5*\@todonotes@currentfigheight-0.5cm)
     rectangle +(\@todonotes@currentfigwidth, \@todonotes@currentfigheight);
 \draw (2, -0.5) node[right, text
-    width=\@todonotes@currentfigwidth-4.5cm, font=\@todonotes@sizecommand] {#2};
+    width=\@todonotes@currentfigwidth-4.5cm, font=\@todonotes@useSizeCommand] {#2};
 \draw[red, fill=white, rounded corners = 1pt, line width=10pt]
     (30:2cm) -- (150:2cm) -- (270:2cm) -- cycle;
 \draw (0, 0.3) node {\@todonotes@MissingFigureUp};