diff --git a/src/libstore/binary-cache-store.cc b/src/libstore/binary-cache-store.cc
index 3cf2da70d..49077524f 100644
--- a/src/libstore/binary-cache-store.cc
+++ b/src/libstore/binary-cache-store.cc
@@ -208,7 +208,7 @@ ref<const ValidPathInfo> BinaryCacheStore::addToStoreCommon(
     if (config.writeNARListing) {
         nlohmann::json j = {
             {"version", 1},
-            {"root", listNar(ref<SourceAccessor>(narAccessor), CanonPath::root, true)},
+            {"root", listNar(*narAccessor, CanonPath::root, true)},
         };
 
         upsertFile(std::string(info.path.hashPart()) + ".ls", j.dump(), "application/json");
diff --git a/src/libstore/remote-fs-accessor.cc b/src/libstore/remote-fs-accessor.cc
index 582599f0d..e2c8f65a7 100644
--- a/src/libstore/remote-fs-accessor.cc
+++ b/src/libstore/remote-fs-accessor.cc
@@ -39,7 +39,7 @@ ref<SourceAccessor> RemoteFSAccessor::addToCache(std::string_view hashPart, std:
 
     if (cacheDir != "") {
         try {
-            nlohmann::json j = listNar(narAccessor, CanonPath::root, true);
+            nlohmann::json j = listNar(*narAccessor, CanonPath::root, true);
             writeFile(makeCacheFile(hashPart, "ls"), j.dump());
         } catch (...) {
             ignoreExceptionExceptInterrupt();
diff --git a/src/libutil/include/nix/util/nar-accessor.hh b/src/libutil/include/nix/util/nar-accessor.hh
index bfba5da73..df7b0fcf2 100644
--- a/src/libutil/include/nix/util/nar-accessor.hh
+++ b/src/libutil/include/nix/util/nar-accessor.hh
@@ -38,6 +38,6 @@ ref<SourceAccessor> makeLazyNarAccessor(const nlohmann::json & listing, GetNarBy
  * Write a JSON representation of the contents of a NAR (except file
  * contents).
  */
-nlohmann::json listNar(ref<SourceAccessor> accessor, const CanonPath & path, bool recurse);
+nlohmann::json listNar(SourceAccessor & accessor, const CanonPath & path, bool recurse);
 
 } // namespace nix
diff --git a/src/libutil/nar-accessor.cc b/src/libutil/nar-accessor.cc
index 6bcdf5f13..12db8ac7b 100644
--- a/src/libutil/nar-accessor.cc
+++ b/src/libutil/nar-accessor.cc
@@ -274,9 +274,9 @@ GetNarBytes seekableGetNarBytes(const Path & path)
 
 using nlohmann::json;
 
-json listNar(ref<SourceAccessor> accessor, const CanonPath & path, bool recurse)
+json listNar(SourceAccessor & accessor, const CanonPath & path, bool recurse)
 {
-    auto st = accessor->lstat(path);
+    auto st = accessor.lstat(path);
 
     json obj = json::object();
 
@@ -295,7 +295,7 @@ json listNar(ref<SourceAccessor> accessor, const CanonPath & path, bool recurse)
         {
             obj["entries"] = json::object();
             json & res2 = obj["entries"];
-            for (const auto & [name, type] : accessor->readDirectory(path)) {
+            for (const auto & [name, type] : accessor.readDirectory(path)) {
                 if (recurse) {
                     res2[name] = listNar(accessor, path / name, true);
                 } else
@@ -305,7 +305,7 @@ json listNar(ref<SourceAccessor> accessor, const CanonPath & path, bool recurse)
         break;
     case SourceAccessor::Type::tSymlink:
         obj["type"] = "symlink";
-        obj["target"] = accessor->readLink(path);
+        obj["target"] = accessor.readLink(path);
         break;
     case SourceAccessor::Type::tBlock:
     case SourceAccessor::Type::tChar:
diff --git a/src/nix/cat.cc b/src/nix/cat.cc
index 114e8d38e..5c3d7cfd4 100644
--- a/src/nix/cat.cc
+++ b/src/nix/cat.cc
@@ -80,7 +80,7 @@ struct CmdCatNar : StoreCommand, MixCat
             throw SysError("opening NAR file '%s'", narPath);
         auto source = FdSource{fd.get()};
         auto narAccessor = makeNarAccessor(source);
-        auto listing = listNar(narAccessor, CanonPath::root, true);
+        auto listing = listNar(*narAccessor, CanonPath::root, true);
         cat(makeLazyNarAccessor(listing, seekableGetNarBytes(narPath)), CanonPath{path});
     }
 };
diff --git a/src/nix/ls.cc b/src/nix/ls.cc
index ca6e20be8..ccd479c0a 100644
--- a/src/nix/ls.cc
+++ b/src/nix/ls.cc
@@ -85,7 +85,7 @@ struct MixLs : virtual Args, MixJSON
         if (json) {
             if (showDirectory)
                 throw UsageError("'--directory' is useless with '--json'");
-            logger->cout("%s", listNar(accessor, path, recursive));
+            logger->cout("%s", listNar(*accessor, path, recursive));
         } else
             listText(accessor, std::move(path));
     }
@@ -150,7 +150,7 @@ struct CmdLsNar : Command, MixLs
             throw SysError("opening NAR file '%s'", narPath);
         auto source = FdSource{fd.get()};
         auto narAccessor = makeNarAccessor(source);
-        auto listing = listNar(narAccessor, CanonPath::root, true);
+        auto listing = listNar(*narAccessor, CanonPath::root, true);
         list(makeLazyNarAccessor(listing, seekableGetNarBytes(narPath)), CanonPath{path});
     }
 };