diff --git a/src/libstore/legacy-ssh-store.cc b/src/libstore/legacy-ssh-store.cc
index b52de5434..5dee25308 100644
--- a/src/libstore/legacy-ssh-store.cc
+++ b/src/libstore/legacy-ssh-store.cc
@@ -120,7 +120,7 @@ struct LegacySSHStore : public Store
         });
     }
 
-    void addToStore(const ValidPathInfo & info, const ref<std::string> & nar,
+    void addToStore(const ValidPathInfo & info, Source & source,
         RepairFlag repair, CheckSigsFlag checkSigs,
         std::shared_ptr<FSAccessor> accessor) override
     {
@@ -131,7 +131,7 @@ struct LegacySSHStore : public Store
         conn->to
             << cmdImportPaths
             << 1;
-        conn->to(*nar);
+        copyNAR(source, conn->to);
         conn->to
             << exportMagic
             << info.path