diff --git a/src/libexpr/flake/lockfile.cc b/src/libexpr/flake/lockfile.cc
index f3ea9063f..3e99fb2d4 100644
--- a/src/libexpr/flake/lockfile.cc
+++ b/src/libexpr/flake/lockfile.cc
@@ -214,12 +214,6 @@ std::ostream & operator <<(std::ostream & stream, const LockFile & lockFile)
     return stream;
 }
 
-void LockFile::write(const Path & path) const
-{
-    createDirs(dirOf(path));
-    writeFile(path, fmt("%s\n", *this));
-}
-
 std::optional<FlakeRef> LockFile::isUnlocked() const
 {
     std::set<ref<const Node>> nodes;
diff --git a/src/libexpr/flake/lockfile.hh b/src/libexpr/flake/lockfile.hh
index ba4c0c848..5a1493404 100644
--- a/src/libexpr/flake/lockfile.hh
+++ b/src/libexpr/flake/lockfile.hh
@@ -65,8 +65,6 @@ struct LockFile
 
     static LockFile read(const Path & path);
 
-    void write(const Path & path) const;
-
     /**
      * Check whether this lock file has any unlocked inputs.
      */