1 files changed, 2 insertions, 2 deletions
diff --git a/src/libstore/misc.cc b/src/libstore/misc.cc
index e894b63db..cc2af61b9 100644
--- a/src/libstore/misc.cc
+++ b/src/libstore/misc.cc
@@ -165,7 +165,7 @@ void Store::queryMissing(const std::vector<DerivedPath> & targets,
         }
 
         std::visit(overloaded {
-          [&](DerivedPath::Built bfd) {
+          [&](const DerivedPath::Built & bfd) {
             if (!isValidPath(bfd.drvPath)) {
                 // FIXME: we could try to substitute the derivation.
                 auto state(state_.lock());
@@ -198,7 +198,7 @@ void Store::queryMissing(const std::vector<DerivedPath> & targets,
                 mustBuildDrv(bfd.drvPath, *drv);
 
           },
-          [&](DerivedPath::Opaque bo) {
+          [&](const DerivedPath::Opaque & bo) {
 
             if (isValidPath(bo.path)) return;