diff --git a/ChangeLog b/ChangeLog
index 959b8d3..b43887a 100755
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,4 +1,4 @@
-2018-06-15
+2018-06-29
 
         * Version 1.6.0 released
         ========================
@@ -14,8 +14,10 @@
         Also compute TS in csspec for On/Off analysis using wstat statistic (#2312)
         Allow specifying of input sky map in ctskymap (#2311)
         Accelerate IRF and RING background methods in ctskymap (#2309)
+        Add upper limit computation is csspec for NODES method (#2233)
         Define MET with respect to the observation time reference or "mjdref"
           parameter (#2054)
+        Implement Python pickeling support (#1938)
 
 
 2018-04-26
diff --git a/NEWS b/NEWS
index 3432c8f..72c5f79 100755
--- a/NEWS
+++ b/NEWS
@@ -1,6 +1,6 @@
 New Features and Important Changes in ctools 1.6.0
 
-20 June 2018
+29 June 2018
 
 
 Introduction
@@ -11,12 +11,12 @@ ctools release with respect to the precedent release.
 
 Configuration
 -------------
-Keep existing library path in installation script on Mac OS X (#2420)
+Keep existing library path in installation script on Mac OS X (#2420).
 
 
 Python interface
 ----------------
-None
+ctools and cscripts can now be pickled from Python (#1938).
 
 
 Support model
@@ -288,6 +288,10 @@ csspec now properly computes the Test Statistic for an On/Off analysis using
 the "wstat" statistic in the case that the input model definition XML file
 did not contain a background model (#2312).
 
+csspec now computes upper limits also for the NODES method by fixing all node
+intensities and varying each node until the log-likelihood increases by a
+certain amount (#2233).
+
 
 cssrcdetect - Detects sources in sky map
 ----------------------------------------
diff --git a/cscripts/csspec.py b/cscripts/csspec.py
index 6e88fb5..6905dff 100755
--- a/cscripts/csspec.py
+++ b/cscripts/csspec.py
@@ -758,6 +758,42 @@ class csspec(ctools.csobservation):
             result['flux']     = spectrum[i*2+1].value() * norm
             result['flux_err'] = spectrum[i*2+1].error() * norm
 
+            # Compute upper flux limit
+            ulimit_value = -1.0
+            if self['calc_ulim'].boolean():
+
+                # Logging information
+                self._log_header3(gammalib.EXPLICIT, 'Computing upper limit')
+
+                # Copy observation container
+                obs = like.obs().copy()
+
+                # Fix intensities of all nodes
+                spectral = obs.models()[self['srcname'].string()].spectral()
+                for par in spectral:
+                    par.fix()
+
+                # Create upper limit object  
+                ulimit = ctools.ctulimit(obs)
+                ulimit['srcname'] = self['srcname'].string()
+                ulimit['parname'] = 'Intensity%d' % i
+                ulimit['eref']    = elogmean.TeV()
+                ulimit['tol']     = 1.0e-3
+
+                # Try to run upper limit and catch exceptions
+                try:
+                    ulimit.run()
+                    ulimit_value = ulimit.diff_ulimit()
+                except:
+                    self._log_string(gammalib.EXPLICIT, 'Upper limit '
+                                     'calculation failed.')
+                    ulimit_value = -1.0
+
+                # Compute upper limit
+                if ulimit_value > 0.0:
+                    result['ulimit'] = ulimit_value * elogmean.MeV() * \
+                                       elogmean.MeV() * gammalib.MeV2erg
+
             # Compute TS
             if self['calc_ts'].boolean():
 
diff --git a/doc/source/admin/release_history/1.6.rst b/doc/source/admin/release_history/1.6.rst
index c50a064..f935326 100644
--- a/doc/source/admin/release_history/1.6.rst
+++ b/doc/source/admin/release_history/1.6.rst
@@ -12,6 +12,7 @@ In particular, this release provides:
 
 * Support for Xspec spectral analysis
 * Improved computation speed for :ref:`ctskymap` and :ref:`csphagen`
+* Support for Python pickeling
 
 
 Bug fixes
@@ -41,6 +42,8 @@ Improvements
   Allow specifying of input skymap to :ref:`ctskymap` tool
 * [`2309 <https://cta-redmine.irap.omp.eu/issues/2309>`_] -
   Accelerate `IRF` and `RING` background methods in :ref:`ctskymap`
+* [`2233 <https://cta-redmine.irap.omp.eu/issues/2233>`_] -
+  Add upper limit computation is :ref:`csspec` for ``NODES`` method
 * [`2045 <https://cta-redmine.irap.omp.eu/issues/2045>`_] -
   Define MET with respect to the observation time reference or the ``mjdref``
   user parameter (#2054)
@@ -49,7 +52,8 @@ Improvements
 New features
 ------------
 
-* ...
+* [`1938 <https://cta-redmine.irap.omp.eu/issues/1938>`_] -
+  Support pickeling of ctools and cscripts in Python
 
 
 Clean up
diff --git a/pyext/ctlikelihood.i b/pyext/ctlikelihood.i
index cf7da7d..b1f8cee 100755
--- a/pyext/ctlikelihood.i
+++ b/pyext/ctlikelihood.i
@@ -1,7 +1,7 @@
 /***************************************************************************
  *              ctlikelihood - Base class for likelihood tools             *
  * ----------------------------------------------------------------------- *
- *  copyright (C) 2016-2017 by Juergen Knoedlseder                         *
+ *  copyright (C) 2016-2018 by Juergen Knoedlseder                         *
  * ----------------------------------------------------------------------- *
  *                                                                         *
  *  This program is free software: you can redistribute it and/or modify   *
@@ -42,14 +42,22 @@
 class cslikelihood : public ctlikelihood  {
 public:
     // Constructors and destructors
-    cslikelihood(const std::string& name, const std::string& version) :
+    cslikelihood(const std::string& name,
+                 const std::string& version) :
                  ctlikelihood(name, version) {}
-    cslikelihood(const std::string& name, const std::string& version,
+    cslikelihood(const std::string&   name,
+                 const std::string&   version,
                  const GObservations& obs) :
                  ctlikelihood(name, version, obs) {}
-    cslikelihood(const std::string& name, const std::string& version,
-                 int argc, char* argv[]) :
-                 ctlikelihood(name, version, argc, argv){}
+    cslikelihood(const std::string&              name,
+                 const std::string&              version,
+                 const std::vector<std::string>& args) :
+                 ctlikelihood(name, version, args) {}
+    cslikelihood(const std::string& name,
+                 const std::string& version,
+                 int                argc,
+                 char*              argv[]) :
+                 ctlikelihood(name, version, argc, argv) {}
     cslikelihood(const cslikelihood& app) : ctlikelihood(app) {}
     virtual ~cslikelihood(void) {}
 
@@ -74,11 +82,18 @@ class ctlikelihood : public ctobservation {
 
 public:
     // Constructors and destructors
-    ctlikelihood(const std::string& name, const std::string& version);
-    ctlikelihood(const std::string& name, const std::string& version,
+    ctlikelihood(const std::string& name,
+                 const std::string& version);
+    ctlikelihood(const std::string&   name,
+                 const std::string&   version,
                  const GObservations& obs);
-    ctlikelihood(const std::string& name, const std::string& version,
-                 int argc, char* argv[]);
+    ctlikelihood(const std::string&              name,
+                 const std::string&              version,
+                 const std::vector<std::string>& args);
+    ctlikelihood(const std::string& name,
+                 const std::string& version,
+                 int                argc,
+                 char*              argv[]);
     ctlikelihood(const ctlikelihood& app);
     virtual ~ctlikelihood(void);
 
@@ -108,11 +123,18 @@ public:
 class cslikelihood : public ctlikelihood  {
 public:        
     // Constructors and destructors
-    cslikelihood(const std::string& name, const std::string& version);
-    cslikelihood(const std::string& name, const std::string& version,
+    cslikelihood(const std::string& name,
+                 const std::string& version);
+    cslikelihood(const std::string&   name,
+                 const std::string&   version,
                  const GObservations& obs);
-    cslikelihood(const std::string& name, const std::string& version,
-                 int ARGC, char **ARGV);
+    cslikelihood(const std::string&              name,
+                 const std::string&              version,
+                 const std::vector<std::string>& args);
+    cslikelihood(const std::string& name,
+                 const std::string& version,
+                 int                ARGC,
+                 char               **ARGV);
     cslikelihood(const cslikelihood& app);
     virtual ~cslikelihood(void);
 
@@ -133,6 +155,21 @@ public:
 /***********************************************************************//**
  * @brief Likelihood tool base class Python extensions
  ***************************************************************************/
+%extend cslikelihood {
+%pythoncode {
+    def __getstate__(self):
+        state = (ctool.__getstate__(self), self.obs())
+        return state
+    def __setstate__(self, state):
+        ctool.__setstate__(self, state[0])
+        self.obs(state[1])
+}
+}
+
+
+/***********************************************************************//**
+ * @brief Likelihood tool base class Python extensions
+ ***************************************************************************/
 %pythoncode %{
 
 # Initialise application by calling the appropriate base class constructor.
@@ -143,7 +180,10 @@ def _init_cslikelihood(self, name, version, argv):
     if len(argv) > 0 and isinstance(argv[0],gammalib.GObservations):
         cslikelihood.__init__(self, name, version, argv[0])
     elif len(argv) > 0:
-        cslikelihood.__init__(self, name, version, *argv)
+        if len(argv) == 3 and argv[0] == name and argv[1] == version:
+            cslikelihood.__init__(self, name, version, argv[2])
+        else:
+            cslikelihood.__init__(self, name, version, *argv)
     else:
         cslikelihood.__init__(self, name, version)
     # Set logger properties
diff --git a/pyext/ctobservation.i b/pyext/ctobservation.i
index 38f221f..7b1bf75 100755
--- a/pyext/ctobservation.i
+++ b/pyext/ctobservation.i
@@ -1,7 +1,7 @@
 /***************************************************************************
  *             ctobservation - Base class for observation tools            *
  * ----------------------------------------------------------------------- *
- *  copyright (C) 2016-2017 by Juergen Knoedlseder                         *
+ *  copyright (C) 2016-2018 by Juergen Knoedlseder                         *
  * ----------------------------------------------------------------------- *
  *                                                                         *
  *  This program is free software: you can redistribute it and/or modify   *
@@ -42,14 +42,22 @@
 class csobservation : public ctobservation  {
 public:
     // Constructors and destructors
-    csobservation(const std::string& name, const std::string& version) :
+    csobservation(const std::string& name,
+                  const std::string& version) :
                   ctobservation(name, version) {}
-    csobservation(const std::string& name, const std::string& version,
+    csobservation(const std::string&   name,
+                  const std::string&   version,
                   const GObservations& obs) :
                   ctobservation(name, version, obs) {}
-    csobservation(const std::string& name, const std::string& version,
-                  int argc, char* argv[]) :
-                  ctobservation(name, version, argc, argv){}
+    csobservation(const std::string&              name,
+                  const std::string&              version,
+                  const std::vector<std::string>& args) :
+                  ctobservation(name, version, args) {}
+    csobservation(const std::string& name,
+                  const std::string& version,
+                  int                argc,
+                  char*              argv[]) :
+                  ctobservation(name, version, argc, argv) {}
     csobservation(const csobservation& app) : ctobservation(app) {}
     virtual ~csobservation(void) {}
 
@@ -74,11 +82,18 @@ class ctobservation : public ctool {
 
 public:
     // Constructors and destructors
-    ctobservation(const std::string& name, const std::string& version);
-    ctobservation(const std::string& name, const std::string& version,
+    ctobservation(const std::string& name,
+                  const std::string& version);
+    ctobservation(const std::string&   name,
+                  const std::string&   version,
                   const GObservations& obs);
-    ctobservation(const std::string& name, const std::string& version,
-                  int ARGC, char **ARGV);
+    ctobservation(const std::string&              name,
+                  const std::string&              version,
+                  const std::vector<std::string>& args);
+    ctobservation(const std::string& name,
+                  const std::string& version,
+                  int                ARGC,
+                  char               **ARGV);
     ctobservation(const ctobservation& app);
     virtual ~ctobservation(void);
 
@@ -120,11 +135,18 @@ public:
 class csobservation : public ctobservation  {
 public:        
     // Constructors and destructors
-    csobservation(const std::string& name, const std::string& version);
-    csobservation(const std::string& name, const std::string& version,
+    csobservation(const std::string& name,
+                  const std::string& version);
+    csobservation(const std::string&   name,
+                  const std::string&   version,
                   const GObservations& obs);
-    csobservation(const std::string& name, const std::string& version,
-                  int ARGC, char **ARGV);
+    csobservation(const std::string&              name,
+                  const std::string&              version,
+                  const std::vector<std::string>& args);
+    csobservation(const std::string& name,
+                  const std::string& version,
+                  int                ARGC,
+                  char               **ARGV);
     csobservation(const csobservation& app);
     virtual ~csobservation(void);
 
@@ -145,6 +167,21 @@ public:
 /***********************************************************************//**
  * @brief Observation tool base class Python extensions
  ***************************************************************************/
+%extend csobservation {
+%pythoncode {
+    def __getstate__(self):
+        state = (ctool.__getstate__(self), self.obs())
+        return state
+    def __setstate__(self, state):
+        ctool.__setstate__(self, state[0])
+        self.obs(state[1])
+}
+}
+
+
+/***********************************************************************//**
+ * @brief Observation tool base class Python extensions
+ ***************************************************************************/
 %pythoncode %{
 
 # Initialise application by calling the appropriate base class constructor.
@@ -155,7 +192,10 @@ def _init_csobservation(self, name, version, argv):
     if len(argv) > 0 and isinstance(argv[0],gammalib.GObservations):
         csobservation.__init__(self, name, version, argv[0])
     elif len(argv) > 0:
-        csobservation.__init__(self, name, version, *argv)
+        if len(argv) == 3 and argv[0] == name and argv[1] == version:
+            csobservation.__init__(self, name, version, argv[2])
+        else:
+            csobservation.__init__(self, name, version, *argv)
     else:
         csobservation.__init__(self, name, version)
     # Set logger properties
diff --git a/pyext/ctool.i b/pyext/ctool.i
index c5bbed7..80137f5 100755
--- a/pyext/ctool.i
+++ b/pyext/ctool.i
@@ -36,9 +36,15 @@
 class cscript : public ctool  {
 public:
     // Constructors and destructors
-    cscript(const std::string& name, const std::string& version) : ctool(name, version) {}
-    cscript(const std::string& name, const std::string& version,
-            int argc, char* argv[]) : ctool(name, version, argc, argv) {}
+    cscript(const std::string& name,
+            const std::string& version) : ctool(name, version) {}
+    cscript(const std::string&              name,
+            const std::string&              version,
+            const std::vector<std::string>& args)  : ctool(name, version, args) {}
+    cscript(const std::string& name,
+            const std::string& version,
+            int                argc,
+            char*              argv[]) : ctool(name, version, argc, argv) {}
     cscript(const ctool& app) : ctool(app) {}
     virtual ~cscript(void) {}
 
@@ -67,9 +73,15 @@ public:
 class ctool : public GApplication  {
 public:
     // Constructors and destructors
-    ctool(const std::string& name, const std::string& version);
-    ctool(const std::string& name, const std::string& version,
-          int ARGC, char **ARGV);
+    ctool(const std::string& name,
+          const std::string& version);
+    ctool(const std::string&              name,
+          const std::string&              version,
+          const std::vector<std::string>& args);
+    ctool(const std::string& name,
+          const std::string& version,
+          int                ARGC,
+          char               **ARGV);
     ctool(const ctool& app);
     virtual ~ctool(void);
 
@@ -219,7 +231,27 @@ public:
         self->m_read_ahead = flag;
         return;
     }
+%pythoncode {
+    def __getstate__(self):
+        state = (gammalib.GApplication.__getstate__(self),)
+        return state
+    def __setstate__(self, state):
+        gammalib.GApplication.__setstate__(self, state[0])
+}
+};
+
+/***********************************************************************//**
+ * @brief ctool base class Python extensions
+ ***************************************************************************/
+%extend cscript {
+%pythoncode {
+    def __getstate__(self):
+        state = (gammalib.GApplication.__getstate__(self),)
+        return state
+    def __setstate__(self, state):
+        gammalib.GApplication.__setstate__(self, state[0])
 }
+};
 
 
 /***********************************************************************//**
@@ -246,6 +278,8 @@ def _init_cscript(self, name, version, argv):
         cscript.__init__(self, name, version)
     elif len(argv) == 1:
         cscript.__init__(self, name, version, *argv)
+    elif len(argv) == 3:
+        cscript.__init__(self, name, version, argv[2])
     else:
         raise TypeError('Invalid number of arguments given.')
     # Set logger properties
diff --git a/pyext/ctools/tools.i b/pyext/ctools/tools.i
index 60229e3..1ba39cc 100755
--- a/pyext/ctools/tools.i
+++ b/pyext/ctools/tools.i
@@ -1,7 +1,7 @@
 /***************************************************************************
  *                           ctools - SWIG file                            *
  * ----------------------------------------------------------------------- *
- *  copyright (C) 2010-2016 by Juergen Knoedlseder                         *
+ *  copyright (C) 2010-2018 by Juergen Knoedlseder                         *
  * ----------------------------------------------------------------------- *
  *                                                                         *
  *  This program is free software: you can redistribute it and/or modify   *
@@ -36,11 +36,13 @@
 
 /* __ Include standard typemaps for vectors and strings __________________ */
 %include stl.i
-%include "std_vector.i"
+%include std_string.i
+%include std_vector.i
 namespace std {
    %template(vector_int)    vector<int>;
    %template(vector_double) vector<double>;
    %template(vector_bool)   vector<bool>;
+   %template(vector_sring)  vector<std::string>;
 };
 
 /* __ Make sure that exceptions are catched ______________________________ */
diff --git a/src/support/ctlikelihood.cpp b/src/support/ctlikelihood.cpp
index 6efcd7e..d251d54 100755
--- a/src/support/ctlikelihood.cpp
+++ b/src/support/ctlikelihood.cpp
@@ -1,7 +1,7 @@
 /***************************************************************************
  *              ctlikelihood - Base class for likelihood tools             *
  * ----------------------------------------------------------------------- *
- *  copyright (C) 2016-2017 by Juergen Knoedlseder                         *
+ *  copyright (C) 2016-2018 by Juergen Knoedlseder                         *
  * ----------------------------------------------------------------------- *
  *                                                                         *
  *  This program is free software: you can redistribute it and/or modify   *
@@ -78,7 +78,30 @@ ctlikelihood::ctlikelihood(const std::string& name,
 ctlikelihood::ctlikelihood(const std::string&   name,
                            const std::string&   version,
                            const GObservations& obs) :
-              ctobservation(name, version, obs)
+                           ctobservation(name, version, obs)
+{
+    // Initialise members
+    init_members();
+
+    // Return
+    return;
+}
+
+
+/***********************************************************************//**
+ * @brief Command line constructor
+ *
+ * @param[in] name Likelihood tool name.
+ * @param[in] version Likelihood tool version.
+ * @param[in] args Arguments vector.
+ *
+ * Constructs a likelihood tool from the @p name, @p version and command
+ * line arguments. See the equivalent ctool constructor for details.
+ ***************************************************************************/
+ctlikelihood::ctlikelihood(const std::string&              name,
+                           const std::string&              version,
+                           const std::vector<std::string>& args) :
+                           ctobservation(name, version, args)
 {
     // Initialise members
     init_members();
@@ -103,7 +126,7 @@ ctlikelihood::ctlikelihood(const std::string& name,
                            const std::string& version,
                            int   argc,
                            char *argv[]) :
-              ctobservation(name, version, argc, argv)
+                           ctobservation(name, version, argc, argv)
 {
     // Initialise members
     init_members();
diff --git a/src/support/ctlikelihood.hpp b/src/support/ctlikelihood.hpp
index 399b80d..8ffb9a9 100755
--- a/src/support/ctlikelihood.hpp
+++ b/src/support/ctlikelihood.hpp
@@ -1,7 +1,7 @@
 /***************************************************************************
  *              ctlikelihood - Base class for likelihood tools             *
  * ----------------------------------------------------------------------- *
- *  copyright (C) 2016-2017 by Juergen Knoedlseder                         *
+ *  copyright (C) 2016-2018 by Juergen Knoedlseder                         *
  * ----------------------------------------------------------------------- *
  *                                                                         *
  *  This program is free software: you can redistribute it and/or modify   *
@@ -42,11 +42,18 @@ class ctlikelihood : public ctobservation {
 
 public:
     // Constructors and destructors
-    ctlikelihood(const std::string& name, const std::string& version);
-    ctlikelihood(const std::string& name, const std::string& version,
+    ctlikelihood(const std::string& name,
+                 const std::string& version);
+    ctlikelihood(const std::string&   name,
+                 const std::string&   version,
                  const GObservations& obs);
-    ctlikelihood(const std::string& name, const std::string& version,
-                 int argc, char* argv[]);
+    ctlikelihood(const std::string&              name,
+                 const std::string&              version,
+                 const std::vector<std::string>& args);
+    ctlikelihood(const std::string& name,
+                 const std::string& version,
+                 int                argc,
+                 char*              argv[]);
     ctlikelihood(const ctlikelihood& app);
     virtual ~ctlikelihood(void);
 
diff --git a/src/support/ctobservation.cpp b/src/support/ctobservation.cpp
index e6511ec..170167d 100755
--- a/src/support/ctobservation.cpp
+++ b/src/support/ctobservation.cpp
@@ -93,6 +93,29 @@ ctobservation::ctobservation(const std::string&   name,
  *
  * @param[in] name Observation tool name.
  * @param[in] version Observation tool version.
+ * @param[in] args Arguments vector.
+ *
+ * Constructs a observation tool from the @p name, @p version and command
+ * line arguments. See the equivalent ctool constructor for details.
+ ***************************************************************************/
+ctobservation::ctobservation(const std::string&              name,
+                             const std::string&              version,
+                             const std::vector<std::string>& args) :
+                             ctool(name, version, args)
+{
+    // Initialise members
+    init_members();
+
+    // Return
+    return;
+}
+
+
+/***********************************************************************//**
+ * @brief Command line constructor
+ *
+ * @param[in] name Observation tool name.
+ * @param[in] version Observation tool version.
  * @param[in] argc Number of arguments in command line.
  * @param[in] argv Array of command line arguments.
  *
diff --git a/src/support/ctobservation.hpp b/src/support/ctobservation.hpp
index 797ac92..3548580 100755
--- a/src/support/ctobservation.hpp
+++ b/src/support/ctobservation.hpp
@@ -45,11 +45,18 @@ class ctobservation : public ctool {
 
 public:
     // Constructors and destructors
-    ctobservation(const std::string& name, const std::string& version);
-    ctobservation(const std::string& name, const std::string& version,
+    ctobservation(const std::string& name,
+                  const std::string& version);
+    ctobservation(const std::string&   name,
+                  const std::string&   version,
                   const GObservations& obs);
-    ctobservation(const std::string& name, const std::string& version,
-                  int argc, char* argv[]);
+    ctobservation(const std::string&              name,
+                  const std::string&              version,
+                  const std::vector<std::string>& args);
+    ctobservation(const std::string& name,
+                  const std::string& version,
+                  int                argc,
+                  char*              argv[]);
     ctobservation(const ctobservation& app);
     virtual ~ctobservation(void);
 
diff --git a/src/support/ctool.cpp b/src/support/ctool.cpp
index 0e8f7cc..715815e 100755
--- a/src/support/ctool.cpp
+++ b/src/support/ctool.cpp
@@ -116,6 +116,58 @@ ctool::ctool(const std::string& name,
  *
  * @param[in] name Application name.
  * @param[in] version Application version.
+ * @param[in] args Arguments vector.
+ *
+ * Constructs a ctool from the @p name, @p version and command line
+ * arguments. The constructor uses the equivalent GApplication constructor
+ * to set the parameter filename to "<name>.par" and the log filename to
+ * "<name>".log. The parameters will be loaded from the parameter file.
+ * In addition, the constructor opens the log file.
+ *
+ * If the "--help" option is provided as command line argument a help text
+ * about the usage of the ctool will be shown in the console and the ctool
+ * will exit. No log file will be opened in that case.
+ ***************************************************************************/
+ctool::ctool(const std::string&              name,
+             const std::string&              version,
+             const std::vector<std::string>& args) : GApplication(name, version, args)
+{
+    // Catch --help option before doing anything else
+    if (need_help()) {
+        provide_help();
+        exit(0);
+    }
+
+    // Initialise members
+    init_members();
+
+    // If CTOOLS environment variable is set and if a parameter exists in
+    // the syspfiles folder then set syspfiles folder and reload parameter
+    // file
+    char* ptr = std::getenv("CTOOLS");
+    if (ptr != NULL) {
+        std::string path     = std::string(ptr) + "/syspfiles";
+        std::string filename = path +  "/" + par_filename();
+        if (access(filename.c_str(), R_OK) == 0) {
+            m_pars.clear();
+            m_pars.syspfiles(path);
+            m_pars.load(par_filename(), m_args);
+        }
+    }
+
+    // Open the log file
+    logFileOpen();
+
+    // Return
+    return;
+}
+
+
+/***********************************************************************//**
+ * @brief Command line constructor
+ *
+ * @param[in] name Application name.
+ * @param[in] version Application version.
  * @param[in] argc Number of arguments in command line.
  * @param[in] argv Array of command line arguments.
  *
diff --git a/src/support/ctool.hpp b/src/support/ctool.hpp
index 7b09697..f7a287a 100755
--- a/src/support/ctool.hpp
+++ b/src/support/ctool.hpp
@@ -50,9 +50,15 @@
 class ctool : public GApplication  {
 public:
     // Constructors and destructors
-    ctool(const std::string& name, const std::string& version);
-    ctool(const std::string& name, const std::string& version,
-          int argc, char* argv[]);
+    ctool(const std::string& name,
+          const std::string& version);
+    ctool(const std::string&              name,
+          const std::string&              version,
+          const std::vector<std::string>& args);
+    ctool(const std::string& name,
+          const std::string& version,
+          int                argc,
+          char*              argv[]);
     ctool(const ctool& app);
     virtual ~ctool(void);
 
diff --git a/test/test_cscaldb.py b/test/test_cscaldb.py
index 0376c9f..afa4320 100755
--- a/test/test_cscaldb.py
+++ b/test/test_cscaldb.py
@@ -18,7 +18,6 @@
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 #
 # ==========================================================================
-#import gammalib
 import cscripts
 from testing import test
 
@@ -34,7 +33,7 @@ class Test(test):
     # Constructor
     def __init__(self):
         """
-        Constructor.
+        Constructor
         """
         # Call base class constructor
         test.__init__(self)
@@ -45,7 +44,7 @@ class Test(test):
     # Set test functions
     def set(self):
         """
-        Set all test functions.
+        Set all test functions
         """
         # Set test name
         self.name('cscaldb')
@@ -53,6 +52,7 @@ class Test(test):
         # Append tests
         self.append(self._test_cmd, 'Test cscaldb on command line')
         self.append(self._test_python, 'Test cscaldb from Python')
+        self.append(self._test_pickeling, 'Test cscaldb pickeling')
 
         # Return
         return
@@ -60,7 +60,7 @@ class Test(test):
     # Test cscaldb on command line
     def _test_cmd(self):
         """
-        Test cscaldb on the command line.
+        Test cscaldb on the command line
         """
         # Set script name
         cscaldb = self._script('cscaldb')
@@ -81,7 +81,7 @@ class Test(test):
     # Test cscaldb from Python
     def _test_python(self):
         """
-        Test cscaldb from Python.
+        Test cscaldb from Python
         """
         # Set-up cscaldb
         caldb = cscripts.cscaldb()
@@ -94,3 +94,26 @@ class Test(test):
 
         # Return
         return
+
+    # Test cscaldb pickeling
+    def _test_pickeling(self):
+        """
+        Test cscaldb pickeling
+        """
+        # Perform pickeling tests of empty class
+        self._pickeling(cscripts.cscaldb())
+
+        # Set-up cscaldb
+        caldb = cscripts.cscaldb()
+        caldb['logfile'] = 'cscaldb_py1_pickle.log'
+        caldb['chatter'] = 2
+
+        # Perform pickeling tests of filled class
+        obj = self._pickeling(caldb)
+
+        # Run script
+        obj.logFileOpen()   # Make sure we get a log file
+        obj.run()
+
+        # Return
+        return
diff --git a/test/test_cslightcrv.py b/test/test_cslightcrv.py
index abbc507..cad4547 100755
--- a/test/test_cslightcrv.py
+++ b/test/test_cslightcrv.py
@@ -33,7 +33,7 @@ class Test(test):
     This test class makes unit tests for the cslightcrv script by using it
     from the command line and from Python.
     """
-    
+
     # Constructor
     def __init__(self):
         """
@@ -60,6 +60,7 @@ class Test(test):
         # Append tests
         self.append(self._test_cmd, 'Test cslightcrv on command line')
         self.append(self._test_python, 'Test cslightcrv from Python')
+        self.append(self._test_pickeling, 'Test cslightcrv pickeling')
 
         # Return
         return
@@ -274,6 +275,45 @@ class Test(test):
         # Return
         return
 
+    # Test cslightcrv pickeling
+    def _test_pickeling(self):
+        """
+        Test cslightcrv pickeling
+        """
+        # Perform pickeling tests of empty class
+        self._pickeling(cscripts.cslightcrv())
+
+        # Set-up unbinned cslightcrv
+        lcrv = cscripts.cslightcrv()
+        lcrv['inobs']    = self._events
+        lcrv['inmodel']  = self._model
+        lcrv['srcname']  = 'Crab'
+        lcrv['caldb']    = self._caldb
+        lcrv['irf']      = self._irf
+        lcrv['tbinalg']  = 'LIN'
+        lcrv['tmin']     = '2020-01-01T00:00:00'
+        lcrv['tmax']     = '2020-01-01T00:05:00'
+        lcrv['tbins']    = 3
+        lcrv['method']   = '3D'
+        lcrv['enumbins'] = 0
+        lcrv['emin']     = 0.1
+        lcrv['emax']     = 100.0
+        lcrv['outfile']  = 'cslightcrv_py1_pickle.fits'
+        lcrv['logfile']  = 'cslightcrv_py1_pickle.log'
+        lcrv['chatter']  = 2
+        lcrv['publish']  = True
+
+        # Perform pickeling tests of filled class
+        obj = self._pickeling(lcrv)
+
+        # Run cslightcrv script and save light curve
+        obj.logFileOpen()   # Make sure we get a log file
+        obj.run()
+        obj.save()
+
+        # Return
+        return
+
     # Check light curve result file
     def _check_light_curve(self, filename, bins, prefactor=5.7e-16):
         """
@@ -312,6 +352,6 @@ class Test(test):
 
         # Close FITS file
         fits.close()
-        
+
         # Return
         return
diff --git a/test/test_cstsmapsplit.py b/test/test_cstsmapsplit.py
index 5fee17c..04f5e9a 100755
--- a/test/test_cstsmapsplit.py
+++ b/test/test_cstsmapsplit.py
@@ -56,6 +56,7 @@ class Test(test):
         # Append tests
         self.append(self._test_cmd, 'Test cstsmapsplit on command line')
         self.append(self._test_python, 'Test cstsmapsplit from Python')
+        self.append(self._test_pickeling, 'Test cstsmapsplit pickeling')
 
         # Return
         return
@@ -178,6 +179,46 @@ class Test(test):
         # Return
         return
 
+    # Test cstsmapsplit pickeling
+    def _test_pickeling(self):
+        """
+        Test cstsmapsplit pickeling
+        """
+        # Perform pickeling tests of empty class
+        self._pickeling(cscripts.cstsmapsplit())
+
+        # Set-up cstsmapsplit
+        tsmapsplit = cscripts.cstsmapsplit()
+        tsmapsplit['inobs']        = self._events
+        tsmapsplit['inmodel']      = self._model
+        tsmapsplit['srcname']      = 'Crab'
+        tsmapsplit['caldb']        = self._caldb
+        tsmapsplit['irf']          = self._irf
+        tsmapsplit['outmap']       = 'tsmap.fits'
+        tsmapsplit['bins_per_job'] = 5
+        tsmapsplit['compute_null'] = False
+        tsmapsplit['outfile']      = 'cstsmapsplit_py1_pickle.dat'
+        tsmapsplit['nxpix']        = 5
+        tsmapsplit['nypix']        = 5
+        tsmapsplit['binsz']        = 0.05
+        tsmapsplit['coordsys']     = 'CEL'
+        tsmapsplit['xref']         = 83.6331
+        tsmapsplit['yref']         = 22.01
+        tsmapsplit['proj']         = 'CAR'
+        tsmapsplit['logfile']      = 'cstsmapsplit_py1_pickle.log'
+        tsmapsplit['chatter']      = 2
+
+        # Perform pickeling tests of filled class
+        obj = self._pickeling(tsmapsplit)
+
+        # Run cstsmapsplit script and save the commands
+        obj.logFileOpen()   # Make sure we get a log file
+        obj.run()
+        obj.save()
+
+        # Return
+        return
+
     # Check observation definition XML file
     def _check_cmdfile(self, filename):
         """
diff --git a/test/testing.py.in b/test/testing.py.in
index b1437e0..3a49aff 100755
--- a/test/testing.py.in
+++ b/test/testing.py.in
@@ -18,6 +18,8 @@
 #
 # ==========================================================================
 import os
+import sys
+import pickle
 import gammalib
 
 
@@ -232,3 +234,36 @@ class test(gammalib.GPythonTestSuite):
 
         # Return
         return
+
+    # Test pickeling
+    def _pickeling(self, object):
+        """
+        Test class pickeling
+
+        Parameters
+        ----------
+        object : `~gammalib.GBase`
+            Class instance
+        """
+        # Get class name
+        name = object.__class__.__name__
+    
+        # Start exception catching
+        self.test_try('Test pickeling of "%s" class.' % name)
+
+        # Test if pickling results in an exception
+        try:
+            dump       = pickle.dumps(object)
+            obj        = pickle.loads(dump)
+            dump_again = pickle.dumps(obj)
+            self.test_assert(dump == dump_again,
+                             'Check pickled dump of "%s\n%s\n%s"' %
+                             (name, str(object), str(obj)))
+            self.test_try_success()
+        except:
+            _, e, _ = sys.exc_info()
+            self.test_try_failure('Error in pickeling "%s" (%s).' %
+                                  (name, str(e)))
+
+        # Return
+        return obj