diff --git a/include/GLog.hpp b/include/GLog.hpp
index e743c62..3d99ffc 100644
--- a/include/GLog.hpp
+++ b/include/GLog.hpp
@@ -1,7 +1,7 @@
 /***************************************************************************
  *                       GLog.hpp - Information logger                     *
  * ----------------------------------------------------------------------- *
- *  copyright (C) 2010-2016 by Juergen Knoedlseder                         *
+ *  copyright (C) 2010-2017 by Juergen Knoedlseder                         *
  * ----------------------------------------------------------------------- *
  *                                                                         *
  *  This program is free software: you can redistribute it and/or modify   *
@@ -121,7 +121,7 @@ protected:
     void        header(const std::string& arg, int level);
     std::string strdate(void) const;
     std::string prefix(void) const;
-    void        append(std::string arg);
+    void        append(const std::string& string);
 
     // Protected data members
     int         m_max_length;   //!< Maximum buffer length
diff --git a/src/app/GLog.cpp b/src/app/GLog.cpp
index 19d2ce6..f77cb41 100644
--- a/src/app/GLog.cpp
+++ b/src/app/GLog.cpp
@@ -802,13 +802,16 @@ std::string GLog::prefix(void) const
 /***********************************************************************//**
  * @brief Append string to the buffer
  *
- * @param[in] arg String to append
+ * @param[in] string String to append
  *
  * This method appends a string to the buffer and prepends, if required, the
  * current date and name at the beginning of each line.
  ***************************************************************************/
-void GLog::append(std::string arg)
+void GLog::append(const std::string& string)
 {
+    // Copy string to append
+    std::string arg = string;
+
     // If the buffer is empty and at the beginning of a line or if the last
     // character is a \n then prepend a prefix at the beginning of the string
     // to be inserted.