--- Levels.h.orig	Thu Oct 15 08:59:14 2009
+++ Levels.h	Thu Oct 15 09:00:25 2009
@@ -24,7 +24,7 @@
 class Levels
 {
  public:
-  Levels( int numDirs=0, const char** dirs=NULL );
+  explicit Levels( int numDirs=0, const char** dirs=NULL );
   bool addPath( const char* path );
   bool addLevel( const std::string& file, int rank=-1, int index=-1 );
   int  numLevels();
