diff --git a/pyext/ctool.i b/pyext/ctool.i
index 1fdee62..4e3d25b 100644
--- a/pyext/ctool.i
+++ b/pyext/ctool.i
@@ -136,3 +136,14 @@ public:
     virtual void save(void);
 };
 
+
+/***********************************************************************//**
+ * @brief ctool base class Python extension
+ ***************************************************************************/
+%extend ctool {
+    void read_ahead(const bool& flag) {
+        self->m_read_ahead = flag;
+        return;
+    }
+}
+
diff --git a/src/support/ctool.hpp b/src/support/ctool.hpp
index 0189588..5355efa 100644
--- a/src/support/ctool.hpp
+++ b/src/support/ctool.hpp
@@ -91,12 +91,14 @@ protected:
     GSkyDir         get_mean_pointing(const GObservations& obs);
     size_t          get_current_rss(void);
 
+    // Protected members
+    bool            m_read_ahead; //!< Read ahead parameters
+
 protected:
     // Protected methods
     void           provide_help(void) const;
     
     // Protected members
-    bool           m_read_ahead; //!< Read ahead parameters
     bool           m_use_xml;    //!< Use XML file instead of FITS file for observations
     GTimeReference m_cta_ref;    //!< CTA time reference
 };