diff --git a/src/copy.vala b/src/copy.vala
index 620c27d6d733fd3ba0b38bb2660f4eb62ed2d6d1..bb9a7e94383b41dfbe657396fd3db9b306218ed3 100644
--- a/src/copy.vala
+++ b/src/copy.vala
@@ -24,7 +24,9 @@ namespace GQPE {
      */
     public class Copy {
 
+        /* The input photograph. */
         private static string input;
+        /* The output photograph. */
         private static string output;
 
         /* The option context. */