diff --git a/3-environment.tex b/3-environment.tex
index 9201484..09ebe69 100644
--- a/3-environment.tex
+++ b/3-environment.tex
@@ -20,7 +20,7 @@ It provides a lightweight messaging mechanism implementing the publish-subscribe
 The controller software has out-of-the-box support for this protocol, which allows easy integration of all different device types using the same patterns.
 
 \begin{figure}[htbp]
-\centering\includegraphics[width=0.4\textwidth]{topology.pdf}
+\centering\fbox{\includegraphics[width=0.4\textwidth]{topology.pdf}}
 \caption{The base network topology.}
 \label{fig:topology}
 \end{figure}
diff --git a/topology.graffle/data.plist b/topology.graffle/data.plist
index 2a240a2..da1843c 100644
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diff --git a/topology.pdf b/topology.pdf
index 6a72ff6..dc4405f 100644
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