diff --git a/src/libutil/include/nix/util/source-accessor.hh b/src/libutil/include/nix/util/source-accessor.hh
index 671444e6f..1006895b3 100644
--- a/src/libutil/include/nix/util/source-accessor.hh
+++ b/src/libutil/include/nix/util/source-accessor.hh
@@ -241,10 +241,4 @@ ref<SourceAccessor> makeFSSourceAccessor(std::filesystem::path root);
  */
 ref<SourceAccessor> makeUnionSourceAccessor(std::vector<ref<SourceAccessor>> && accessors);
 
-/**
- * Creates a new source accessor which is confined to the subdirectory
- * of the given source accessor.
- */
-ref<SourceAccessor> projectSubdirSourceAccessor(ref<SourceAccessor>, CanonPath subdirectory);
-
 } // namespace nix
diff --git a/src/libutil/meson.build b/src/libutil/meson.build
index f4b8dbb61..acba0b81b 100644
--- a/src/libutil/meson.build
+++ b/src/libutil/meson.build
@@ -156,7 +156,6 @@ sources = [ config_priv_h ] + files(
   'source-accessor.cc',
   'source-path.cc',
   'strings.cc',
-  'subdir-source-accessor.cc',
   'suggestions.cc',
   'tarfile.cc',
   'tee-logger.cc',
diff --git a/src/libutil/subdir-source-accessor.cc b/src/libutil/subdir-source-accessor.cc
deleted file mode 100644
index d4f57e2f7..000000000
--- a/src/libutil/subdir-source-accessor.cc
+++ /dev/null
@@ -1,59 +0,0 @@
-#include "nix/util/source-accessor.hh"
-
-namespace nix {
-
-struct SubdirSourceAccessor : SourceAccessor
-{
-    ref<SourceAccessor> parent;
-
-    CanonPath subdirectory;
-
-    SubdirSourceAccessor(ref<SourceAccessor> && parent, CanonPath && subdirectory)
-        : parent(std::move(parent))
-        , subdirectory(std::move(subdirectory))
-    {
-        displayPrefix.clear();
-    }
-
-    std::string readFile(const CanonPath & path) override
-    {
-        return parent->readFile(subdirectory / path);
-    }
-
-    void readFile(const CanonPath & path, Sink & sink, std::function<void(uint64_t)> sizeCallback) override
-    {
-        return parent->readFile(subdirectory / path, sink, sizeCallback);
-    }
-
-    bool pathExists(const CanonPath & path) override
-    {
-        return parent->pathExists(subdirectory / path);
-    }
-
-    std::optional<Stat> maybeLstat(const CanonPath & path) override
-    {
-        return parent->maybeLstat(subdirectory / path);
-    }
-
-    DirEntries readDirectory(const CanonPath & path) override
-    {
-        return parent->readDirectory(subdirectory / path);
-    }
-
-    std::string readLink(const CanonPath & path) override
-    {
-        return parent->readLink(subdirectory / path);
-    }
-
-    std::string showPath(const CanonPath & path) override
-    {
-        return displayPrefix + parent->showPath(subdirectory / path) + displaySuffix;
-    }
-};
-
-ref<SourceAccessor> projectSubdirSourceAccessor(ref<SourceAccessor> parent, CanonPath subdirectory)
-{
-    return make_ref<SubdirSourceAccessor>(std::move(parent), std::move(subdirectory));
-}
-
-} // namespace nix