diff --git a/src/libutil/util.cc b/src/libutil/util.cc
index 192ff528a..740d767a4 100644
--- a/src/libutil/util.cc
+++ b/src/libutil/util.cc
@@ -326,25 +326,6 @@ void deletePath(const Path & path, unsigned long long & bytesFreed)
 }
 
 
-void makePathReadOnly(const Path & path)
-{
-    checkInterrupt();
-
-    struct stat st = lstat(path);
-
-    if (!S_ISLNK(st.st_mode) && (st.st_mode & S_IWUSR)) {
-        if (chmod(path.c_str(), st.st_mode & ~S_IWUSR) == -1)
-            throw SysError(format("making `%1%' read-only") % path);
-    }
-
-    if (S_ISDIR(st.st_mode)) {
-        Strings names = readDirectory(path);
-        for (Strings::iterator i = names.begin(); i != names.end(); ++i)
-            makePathReadOnly(path + "/" + *i);
-    }
-}
-
-
 static Path tempName(Path tmpRoot, const Path & prefix, bool includePid,
     int & counter)
 {
diff --git a/src/libutil/util.hh b/src/libutil/util.hh
index c5c3fb2c3..0351220c2 100644
--- a/src/libutil/util.hh
+++ b/src/libutil/util.hh
@@ -85,9 +85,6 @@ void deletePath(const Path & path);
 
 void deletePath(const Path & path, unsigned long long & bytesFreed);
 
-/* Make a path read-only recursively. */
-void makePathReadOnly(const Path & path);
-
 /* Create a temporary directory. */
 Path createTempDir(const Path & tmpRoot = "", const Path & prefix = "nix",
     bool includePid = true, bool useGlobalCounter = true, mode_t mode = 0755);