diff --git a/src/gsi/gsi.pro b/src/gsi/gsi.pro
index ec23077f7..1fba8435b 100644
--- a/src/gsi/gsi.pro
+++ b/src/gsi/gsi.pro
@@ -18,6 +18,7 @@ SOURCES = \
   gsiExternalMain.cc \
   gsiInterpreter.cc \
   gsiMethods.cc \
+  gsiInspector.cc \
   gsiObject.cc \
   gsiSerialisation.cc \
   gsiTypes.cc \
diff --git a/src/gsi/gsiInspector.cc b/src/gsi/gsiInspector.cc
new file mode 100644
index 000000000..4858973b7
--- /dev/null
+++ b/src/gsi/gsiInspector.cc
@@ -0,0 +1,95 @@
+
+/*
+
+  KLayout Layout Viewer
+  Copyright (C) 2006-2017 Matthias Koefferlein
+
+  This program is free software; you can redistribute it and/or modify
+  it under the terms of the GNU General Public License as published by
+  the Free Software Foundation; either version 2 of the License, or
+  (at your option) any later version.
+
+  This program is distributed in the hope that it will be useful,
+  but WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+  GNU General Public License for more details.
+
+  You should have received a copy of the GNU General Public License
+  along with this program; if not, write to the Free Software
+  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+
+*/
+
+
+#include "gsiInspector.h"
+
+namespace gsi
+{
+
+Inspector::Inspector ()
+{
+  //  .. the base class implementation does nothing ..
+}
+
+Inspector::~Inspector ()
+{
+  //  .. the base class implementation does nothing ..
+}
+
+std::string Inspector::description () const
+{
+  return std::string ();
+}
+
+bool Inspector::has_keys () const
+{
+  return true;
+}
+
+std::string Inspector::key (size_t /*index*/) const
+{
+  return std::string ();
+}
+  
+tl::Variant Inspector::keyv (size_t /*index*/) const
+{
+  return tl::Variant ();
+}
+
+std::string Inspector::type (size_t /*index*/) const
+{
+  return std::string ();
+}
+
+Inspector::Visibility Inspector::visibility (size_t /*index*/) const
+{
+  return Always;
+}
+
+tl::Variant Inspector::value (size_t /*index*/) const
+{
+  return tl::Variant ();
+}
+
+size_t Inspector::count () const
+{
+  return 0;
+}
+
+bool Inspector::has_children (size_t /*index*/) const
+{
+  return false;
+}
+
+Inspector *Inspector::child_inspector (size_t /*index*/) const
+{
+  return 0;
+}
+
+bool Inspector::equiv (const gsi::Inspector * /*other*/) const
+{
+  return false;
+}
+
+}
+
diff --git a/src/gsi/gsiInspector.h b/src/gsi/gsiInspector.h
index ac425e678..f32e00754 100644
--- a/src/gsi/gsiInspector.h
+++ b/src/gsi/gsiInspector.h
@@ -69,68 +69,44 @@ public:
   /**
    *  @brief Constructor
    */
-  Inspector ()
-  {
-    //  .. the base class implementation does nothing ..
-  }
+  Inspector ();
 
   /**
    *  @brief Destructor
    */
-  virtual ~Inspector ()
-  {
-    //  .. the base class implementation does nothing ..
-  }
+  virtual ~Inspector ();
 
   /**
    *  @brief Returns a text describing the namespace the inspector will deliver
    *  This method will be used to label the node if "has_children" is true.
    */
-  virtual std::string description () const
-  {
-    return std::string ();
-  }
+  virtual std::string description () const;
 
   /**
    *  @brief Returns true if the inspector does not deliver keys but indexes only
    */
-  virtual bool has_keys () const
-  {
-    return true;
-  }
+  virtual bool has_keys () const;
 
   /**
    *  @brief Gets the key (name) of the element given by the index
    */
-  virtual std::string key (size_t /*index*/) const
-  {
-    return std::string ();
-  }
+  virtual std::string key (size_t /*index*/) const;
   
   /**
    *  @brief Gets the key (name) of the element given by the index as a tl::Variant
    *  If the string key returns an empty value, the evaluation will fall back to the tl::Variant.
    */
-  virtual tl::Variant keyv (size_t /*index*/) const
-  {
-    return tl::Variant ();
-  }
+  virtual tl::Variant keyv (size_t /*index*/) const;
 
   /**
    *  @brief Gets the value indicating the type of the entry
    */
-  virtual std::string type (size_t /*index*/) const
-  {
-    return std::string ();
-  }
+  virtual std::string type (size_t /*index*/) const;
 
   /**
    *  @brief Gets the value indicating the visibility of the entry
    */
-  virtual Visibility visibility (size_t /*index*/) const
-  {
-    return Always;
-  }
+  virtual Visibility visibility (size_t /*index*/) const;
 
   /**
    *  @brief Gets the value for the element given by the index
@@ -138,48 +114,33 @@ public:
    *  This method needs to deliver a value when the node is a leaf
    *  node (i.e. has_children is false).
    */
-  virtual tl::Variant value (size_t /*index*/) const
-  {
-    return tl::Variant ();
-  }
+  virtual tl::Variant value (size_t /*index*/) const;
 
   /**
    *  @brief Returns the number of elements this inspector can deliver
    *
    *  The index values for the methods of the inspector must be between 0 and count-1.
    */
-  virtual size_t count () const
-  {
-    return 0;
-  }
+  virtual size_t count () const;
 
   /**
    *  @brief Returns a value indicating whether the given element has children
    */
-  virtual bool has_children (size_t /*index*/) const
-  {
-    return false;
-  }
+  virtual bool has_children (size_t /*index*/) const;
 
   /**
    *  @brief Returns an inspector object for the children of the element given by index
    *  The child inspector is used if has_children is true.
    *  The returned object must be deleted by the caller.
    */
-  virtual Inspector *child_inspector (size_t /*index*/) const
-  {
-    return 0;
-  }
+  virtual Inspector *child_inspector (size_t /*index*/) const;
 
   /**
    *  @brief Returns a value indicating whether the inspectors are equivalent
    *  The system uses this information to determine whether to update the full variable
    *  list or just the changed information.
    */
-  virtual bool equiv (const gsi::Inspector * /*other*/) const
-  {
-    return false;
-  }
+  virtual bool equiv (const gsi::Inspector * /*other*/) const;
 };
 
 }