1 files changed, 1 insertions, 0 deletions
diff --git a/src/nix/copy.cc b/src/nix/copy.cc
index 8d7c6a0e8e4c..071ac3890aa9 100644
--- a/src/nix/copy.cc
+++ b/src/nix/copy.cc
@@ -17,6 +17,7 @@ struct CmdCopy : StorePathsCommand
     SubstituteFlag substitute = NoSubstitute;
 
     CmdCopy()
+        : StorePathsCommand(true)
     {
         mkFlag(0, "from", "store-uri", "URI of the source Nix store", &srcUri);
         mkFlag(0, "to", "store-uri", "URI of the destination Nix store", &dstUri);