diff --git a/src/loaders/Conf.cpp b/src/loaders/Conf.cpp
index 2a8b9c3..9f7542d 100644
--- a/src/loaders/Conf.cpp
+++ b/src/loaders/Conf.cpp
@@ -19,10 +19,10 @@ Conf::Conf( std::string filename ): JSON_Loader()
     this->load_json_file( filename, true );
 
     // find the path to the plan file
-    if (! this->get_key( this->plan_path, "plan_path", true) ) { throw CONF_PLANPATH_INVALID(); }
+    if ( this->get_key( this->plan_path, "plan_path", true) != 0 ) { throw CONF_PLANPATH_INVALID(); }
 
     // find the path to the unit definitions file
-    if (! this->get_key( this->units_path, "units_path", true) ) { throw CONF_UNITSPATH_INVALID(); }
+    if ( this->get_key( this->units_path, "units_path", true) != 0 ) { throw CONF_UNITSPATH_INVALID(); }
 };
 
 std::string Conf::get_plan_path()