diff --git a/doc/developer/advance.tex b/doc/developer/advance.tex
index 7763e2d7650dbe7d97224e6c16ab0a0dd88b184f..1f8932359316c700ca728840c37ff5ead4719ebd 100644
--- a/doc/developer/advance.tex
+++ b/doc/developer/advance.tex
@@ -958,6 +958,10 @@ the configuration header of a test (or a test suite).
 & Plugins to be loaded with each subsequent run.
 & \texttt{from inout eva scope variadic} for tests under \texttt{./tests} directory
 \\
+& \texttt{LIBS}\nscodeidxdef{Test!Directive}{LIBS}
+& Libraries to be loaded with each subsequent run (their compilation is not managed by \texttt{ptests} contrary to the modules of \texttt{MODULE} directive).
+& \textit{None}
+\\
 & \texttt{CMD}\nscodeidxdef{Test!Directive}{CMD}
 & Program to run
 & \texttt{./bin/toplevel.opt}
@@ -1166,6 +1170,9 @@ or
   \texttt{@PTEST\_MAKE\_MODULE@} defaults to \texttt{make -s}. Option
   \texttt{-load-module <MODULE>} will then be appended to any subsequent Frama-C
   command triggered by the test.
+\item \texttt{LIBS}\nscodeidx{Test!Directive}{LIBS}
+ directive takes as argument the name of a \texttt{.cmxs}
+  module. The \texttt{-load-module <LIBS>} will then be appended to any subsequent Frama-C command triggered by the test. The compilation is not managed by \texttt{ptests}.
 \item The \texttt{FILEREG}\nscodeidx{Test!Directive}{FILEREG}
   directive contains a regular expression indicating which files in
   the directory containing the current test suite are actually part of
diff --git a/doc/developer/changes.tex b/doc/developer/changes.tex
index cbece5ab43e7ba9114065fea0a77882b5244660c..7ae80ec8fab481029d614b6189111ade287e21c1 100644
--- a/doc/developer/changes.tex
+++ b/doc/developer/changes.tex
@@ -7,7 +7,7 @@ This chapter summarizes the major changes in this documentation between each
 
 \section*{dev}
 \begin{itemize}
-\item \textbf{Testing}: Document new directive \texttt{PLUGIN} and new predefined macros for \texttt{ptests}.
+\item \textbf{Testing}: Document new directives (\texttt{PLUGIN} and \texttt{LIBS}) and new predefined macros for \texttt{ptests}.
 \end{itemize}
 
 \section*{22.0 Titanium}
diff --git a/doc/developer/refman.tex b/doc/developer/refman.tex
index 222fd58a7509a24fefe4b47c07ca1a06134bb1e5..20c0eaa647cc4ad9b6b9352394bbfa3014336507 100644
--- a/doc/developer/refman.tex
+++ b/doc/developer/refman.tex
@@ -871,15 +871,19 @@ one for regular tests (if more than one \verb|OPT|).\\
 \hline
 \verb|PTEST_MODULE| & current list of module defined by the \verb|MODULE| directive\\
 \hline
+\verb|PTEST_LIBS| & current list of module defined by the \verb|LIBS| directive\\
+\hline
 \verb|PTEST_PLUGIN| & current list of plugins defined by the \verb|PLUGIN| directive\\
 \hline
 \verb|PTEST_DEFAULT_OPTIONS| & the default option list: \verb|-journal-disable| \verb|-check| \verb|-no-autoload-plugins|\\
 \hline
 \verb|PTEST_LOAD_MODULE| & the \verb|-load-module| option related to the \verb|MODULE| directive\\
 \hline
+\verb|PTEST_LOAD_LIBS| & the \verb|-load-module| option related to the \verb|LIBS| directive\\
+\hline
 \verb|PTEST_LOAD_PLUGIN| & the \verb|-load-module| option related to the \verb|PLUGIN| directive\\
 \hline
-\verb|PTEST_LOAD_OPTIONS| & shorthand alias to \spverb|@PTEST_LOAD_PLUGIN@ @PTEST_LOAD_MODULE@|\\
+\verb|PTEST_LOAD_OPTIONS| & shorthand alias to \spverb|@PTEST_LOAD_PLUGIN@ @PTEST_LOAD_LIBS@ @PTEST_LOAD_MODULE@|\\
 \hline
 \verb|PTEST_OPTIONS| & the current list of options related to \verb|OPT| and \verb|STDOPT| directives (for \verb|CMD| directives)\\
 \hline