diff --git a/gdb-best-friend.tex b/gdb-best-friend.tex
index eb38818..1bc2b6b 100644
--- a/gdb-best-friend.tex
+++ b/gdb-best-friend.tex
@@ -231,7 +231,7 @@ process("./example-stap").mark("my_probe") $arg1:long
 		\pause
 		\item{Integrated with the \textit{breakpoint} system.  Support for printing a \probe{}'s argument value.}
 		\pause
-		\item{Not necessary to include debug information in your binary (\texttt{-g} flag); arguments are encoded directly in the asm.}
+		\item{\textcolor{red}{Not necessary to include debug information in your binary (\texttt{-g} flag); arguments are encoded directly in the asm.}}
 		\pause
 		\item{Also possible to use optmization flags (\texttt{-O}).}
 	\end{itemize}
@@ -339,7 +339,6 @@ $2 = 10
 
 \begin{frame}[fragile]
 	\frametitle{\python{}$^3$}
-%	\begin{itemize}
 		\begin{block}{caller\_is.py}
 		\tiny
 		\begin{lstlisting}[language=python,showstringspaces=false]
@@ -370,8 +369,16 @@ CallerIs()
 \begin{frame}[fragile]
 	\frametitle{\python{}$^4$}
 	\begin{itemize}
-		\item{\verb|(gdb) source caller_is.py|}
-		\item{\verb|(gdb) break foo if $caller_is ("bar")|}
+		\item{To use it:}
+		\begin{block}{Using caller\_is.py}
+			\tiny
+			\begin{lstlisting}[language=sh,showstringspaces=false]
+(gdb) source caller_is.py
+(gdb) break foo if $caller_is ("bar")
+			\end{lstlisting}
+			\end{block}
+		\item{Internal variables and functions on \gdb{} start with \verb|$|.}
+		\item{\texttt{caller\_is.py} is part of upstream \gdb{}.}
 	\end{itemize}
 \end{frame}